4.2 to 5.3 Swap

Riddlebox0333

Original poster
Member
Jan 24, 2012
6
First off, being a former TV member, YES I did use the search feature. I saw where people were talking about it but not doing it. Has it been done on a 4x4? I have a blown 4.2 and I am looking at all of my options. Thanks.
 

Me007gold

Member
Nov 20, 2011
1,106
It's a lot more trouble then Its worth. You need to ad the v8 crossmember, get all the wiring and PCM and Probley some other stuff as well.
 

djthumper

Administrator
Nov 20, 2011
14,956
North Las Vegas
And changing the rear end to the 8.5
 

RayVoy

Member
Nov 20, 2011
939
djthumper said:
And changing the rear end to the 8.5
And, I sure the overall engine transmission length will be different, changing the position of the transfer case, requiring different driveshafts.
The radiator may be different, the shrouds are for sure.
The underhood wiring will be different, things like power-steering hoses and rad hoses will be different.
And, the list goes on.

But all that aside, I think it would be a fun mod.
 

smitty5150

Member
Nov 18, 2011
1,069
Lots of things need to be done, for sure. I am looking into it myself. Mechanically it is pretty standard for a swap. Electrically you have two options. You need the complete wiring and pcm from a.v8 model or you need to pull all of the factory wiring and go with a universal harness/gauges/etc.

Personally, I think the mod is worth it. I would get a cheap dd and start searching for parts.
 

Riddlebox0333

Original poster
Member
Jan 24, 2012
6
For all of that headache and rewireing, I'd rather dump a bad azzzz LS1 in there. 800hp in 4LO, that would break something.
 

ScarabEpic22

Member
Nov 20, 2011
728
You have an 02, 02-04 I6s should be the easiest to swap a V8 into. Easy to get a GM PCM in there, GM already did it for us! Run a 1MB LS1B PCM out of any 03-07 fullsize truck, find an 03-04 5.3L TrailBlazer pedal assembly and throttle body, full flash an extended TrailBlazer OS into the PCM, retune it for your setup and call it a day. The electronics ARENT that hard for 02-04 (maybe 05s), its above that when you get into the CAN based stuff where it gets tricky. You *might* have to have a dealer reflash your BCM with the firmware of a LWB TrailBlazer, but I cant verify that.

The radiators are different between the I6 and V8s, Id get a V8 one if you want to do the swap. Easiest way to do this would be to find an 03-04 5.3L LWB TrailBlazer/Voy that has been rear-ended and steal all the needed parts from it. Doesnt mean you have to use the 5.3 though, a nice cammed LS1/2/3 would sit nicely in there too. :biggrin:

Ive put this out there before and will again, if anyone in the NW wants to attempt a V8 swap in a truck originally with an 02-04 (05 maybe) I6 I will donate a few hours of time and an EFILive license so you can get it running (VIN change, VATS, engine displacement changes, etc).
 

Riddlebox0333

Original poster
Member
Jan 24, 2012
6
ScarabEpic22 said:
You have an 02, 02-04 I6s should be the easiest to swap a V8 into. Easy to get a GM PCM in there, GM already did it for us! Run a 1MB LS1B PCM out of any 03-07 fullsize truck, find an 03-04 5.3L TrailBlazer pedal assembly and throttle body, full flash an extended TrailBlazer OS into the PCM, retune it for your setup and call it a day. The electronics ARENT that hard for 02-04 (maybe 05s), its above that when you get into the CAN based stuff where it gets tricky. You *might* have to have a dealer reflash your BCM with the firmware of a LWB TrailBlazer, but I cant verify that.

The radiators are different between the I6 and V8s, Id get a V8 one if you want to do the swap. Easiest way to do this would be to find an 03-04 5.3L LWB TrailBlazer/Voy that has been rear-ended and steal all the needed parts from it. Doesnt mean you have to use the 5.3 though, a nice cammed LS1/2/3 would sit nicely in there too. :biggrin:

Ive put this out there before and will again, if anyone in the NW wants to attempt a V8 swap in a truck originally with an 02-04 (05 maybe) I6 I will donate a few hours of time and an EFILive license so you can get it running (VIN change, VATS, engine displacement changes, etc).

I'm from that area, my brother lives in La Conner and I go there a couple times a year to fish. An LS would be great, but then EVERYTHING in the chain would have to be replaced to handle the HP. Upgrade the tranny, then the transfer case, drive lines, then do a straight axle swap with maybe some Dana 60's front and rear with lockers, then a full roll cage. :undecided: But then I could roast 44" tires down the 1/4 mile :tongue:
 

ScarabEpic22

Member
Nov 20, 2011
728
smitty5150 said:
I am about as far away as you can get from taking that offer, meet half way?:raspberry:

Me007gold said:
You guys are more then welcome to meet down here, I am sure I can find a place for us to work.

Hahaha sorry guys, I want to see it done but Im still currently unemployed and definitely dont have the $$ to pay for the gas.

Riddlebox0333 said:
I'm from that area, my brother lives in La Conner and I go there a couple times a year to fish. An LS would be great, but then EVERYTHING in the chain would have to be replaced to handle the HP. Upgrade the tranny, then the transfer case, drive lines, then do a straight axle swap with maybe some Dana 60's front and rear with lockers, then a full roll cage. :undecided: But then I could roast 44" tires down the 1/4 mile :tongue:

Ah cool, my cousins are from Mt Vernon and one got married in La Conner.

You'd need at least a 4L70E or a built 4L60E, 8.6" diff out of a LWB truck (9.5" diff if you can get one), and a driveshaft if needed anyway for anything bigger than a 5.3L V8. No need to mess with the front end, just dont beat on it in 4WD. Eh you'll have to get pretty wild with a straight engine build (no power adders) to get into the 11s and need a cage. At least 406ci, forged bottom end, BIG cam, upgraded heads, injectors, and a FAST/similar intake. You could built it crazy and roast 44s, but thats another story for another day. :biggrin:
 

djthumper

Administrator
Nov 20, 2011
14,956
North Las Vegas
LOL something that brought Erik back into the forums! Just up his alley.
 

ScarabEpic22

Member
Nov 20, 2011
728
djthumper said:
LOL something that brought Erik back into the forums! Just up his alley.

Ha I try Larry, kinda tricky getting the time these days to get on here long enough to read most of the threads and reply to one or two. :thumbsup:
 

smitty5150

Member
Nov 18, 2011
1,069
This is something I have also wanted to see done for the longest time. Being my dd, its noy something I have ever seriously considered. Now, with the prospect of getting a second vehicle for commuting, I can start to look into actually doing it. Fortunately for me, some people have done a lot of figuring out(thanks, Eric). Not just that, but converting from 4wd to 2wd would allow me to sell off some more good parts to help offset the cost and get it done faster. I'm not as loaded as some and every penny counts.
 

Pittdawg

Member
Dec 5, 2011
538
Riddlebox0333 said:
First off, being a former TV member, YES I did use the search feature. I saw where people were talking about it but not doing it. Has it been done on a 4x4? I have a blown 4.2 and I am looking at all of my options. Thanks.

Replace with a modded 4.2! I'm modding mine and pretty happy so far. Hopefully you still have some good parts like heads, throttle body and exhaust manifold. Get all those pieces ported and polished and drop in a new or used 4.2 after adding those parts, get a tune and your set. No need to worry about wiring, cross members, tranny, etc.
 

smitty5150

Member
Nov 18, 2011
1,069
True, true. Take that, add a shift kit and some Vette servos to the trans and it'll be pretty badass. From what I have read, it'll top out performance-wise about where the v8 leaves you after intake/exhaust/tune. While it does eliminate the bolt on possibilities of s/c or turbo, how much performance do you want from a 4x4 SUV?
 

ScarabEpic22

Member
Nov 20, 2011
728
If you want to spend a little $$ but not go for a V8 swap, for around 2k you should be able to get a set of cams for the I6...efi-diy says they're good for ~40-50rwhp with a proper tune. Throw in a ported head (~20hp), fab some headers, and its probably 280-300rwhp. Thats AWD SS territory for those following along! :cool:
 

smitty5150

Member
Nov 18, 2011
1,069
Assuming that Erik is right(I'm sure he is), this might be a viable option for a PCM:
[EBAY]310369755635[/EBAY]

It's the right type of PCM and they program it for you. I don't know that I am ready to buy just yet, but I think I will contact these guys to see if it is something they can do. I've been window shopping for some 5.3 motors and this is starting to look more feasible than I thought at first glance.

Another option *sort of* is to do a standalone PCM for the motor/trans. While this would get the truck running and driving, a lot of other things would need to be done to retain a lot of the stock accessory function.


If you haven't guessed, this is something I have wanted to do for a while. I have only recently started to look at this seriously.
 

Jkust

Member
Dec 4, 2011
946
The 5.3 gives you a little extra oomph on the low end on up but if I'm you and going through the effort, I would look at an LS1. There are lots of 6.0/tranny packages on Ebay generally and suprisingly cheap with low miles.
 

gmcman

Member
Dec 12, 2011
4,656
Bore the 4.2, get a custom exhaust manifold and add a turbo. Build up the trans, swap the rear and you get to keep most of the plumbing.
 

smitty5150

Member
Nov 18, 2011
1,069
Jkust said:
The 5.3 gives you a little extra oomph on the low end on up but if I'm you and going through the effort, I would look at an LS1. There are lots of 6.0/tranny packages on Ebay generally and suprisingly cheap with low miles.

I am considering it. I have to think about the other upgrades involved also. With a mildly built 5.3, I can reuse my trans with a rebuild, shift kit, etc. But it really isn't hard to find a complete ls1 drivetrain from a camaro or firebird.
 

ScarabEpic22

Member
Nov 20, 2011
728
Jkust said:
The 5.3 gives you a little extra oomph on the low end on up but if I'm you and going through the effort, I would look at an LS1. There are lots of 6.0/tranny packages on Ebay generally and suprisingly cheap with low miles.

LS1 = 5.7L... :raspberry:

LS2 = 6.0L, like it but want more cubes for the SS. Make my 02 pretty fun though, but it'll have to get sold to pay for the built LS3 down the road.

gmcman said:
Bore the 4.2, get a custom exhaust manifold and add a turbo. Build up the trans, swap the rear and you get to keep most of the plumbing.

:wootwoot: I really want to see someone step up to the plate and do this, Id be there but now that I have the SS and dont have a job, not happening. Ill help build it though!

smitty5150 said:
I am considering it. I have to think about the other upgrades involved also. With a mildly built 5.3, I can reuse my trans with a rebuild, shift kit, etc. But it really isn't hard to find a complete ls1 drivetrain from a camaro or firebird.

True, I do know a few SS guys with stock trans + servos that are handling the LS2 + Maggie at low boost. Would I do it personally? No f&%king way, recipe for disaster. But it is possible...

Trans and rear diff are the ones that will cost the most to support a swap like this, I know a few 5.3L guys with Maggies that have swapped rear axles out of an SS in.



And that is the correct PCM, any 03-07 1MB LS1B PCM will work just fine. Fortunately EFILive and HPTuners can full flash the whole PCM so its not a big deal to get one from a Silverado and flashing it for a TrailBlazer with EFILive/HPTuners. Cant do that with E40s, E38s, E67s, etc though.
 

smitty5150

Member
Nov 18, 2011
1,069
When I pull the trigger, rear will be swapped for an ss rear and I will convert to 2wd. I'm not looking to make a complete monster out of this, just a beefy dd that can handle the occasional track day. That, and the satisfaction of being the first known to do a swap without completely gutting and rewiring everything. I know there is the mentality that bigger is better, but I see no reason why a cammed 5.3 with a small supercharger(and a few bolt ons) wouldnt be sufficient. Add that to a slightly built 4l60 or 4l70 and I should be set. Since my drivetrain is 100% operational, I will be able to part it out to help offset costs.


I also would not mind running a turboed 4.2. Something I haven't looked into, though. Not sure how much more difficult that would be, though the benefit of keeping a lot of parts is slightly appealing.
 

gmcman

Member
Dec 12, 2011
4,656
smitty5150 said:
I also would not mind running a turboed 4.2. Something I haven't looked into, though. Not sure how much more difficult that would be, though the benefit of keeping a lot of parts is slightly appealing.

Oh, it would be most appealing....:biggrin:

Pull out the washer fluid reservoir and you could carry a baby kangaroo in there, all kinds of room for extra plumbing if needed.

ScarabEpic22 said:
:wootwoot: I really want to see someone step up to the plate and do this, Id be there but now that I have the SS and dont have a job, not happening. Ill help build it though!

Was it not a pita with the 02 ECM on retuning for forced induction...something like not allowing over 1 bar? Tell me it's doable and I may lose sleep.

If mine ever goes belly up that's what i'm going to try to do. Trans will be worked once it goes so the rear will be the next upgrade. Mr OP....not trying to derail your thread, but someone said .........t u r b o....:undecided: Wait, that was me. :cool:
 

limequat

Member
Dec 8, 2011
520
gmcman said:
Oh, it would be most appealing....:biggrin:

Pull out the washer fluid reservoir and you could carry a baby kangaroo in there, all kinds of room for extra plumbing if needed.



Was it not a pita with the 02 ECM on retuning for forced induction...something like not allowing over 1 bar? Tell me it's doable and I may lose sleep.

If mine ever goes belly up that's what i'm going to try to do. Trans will be worked once it goes so the rear will be the next upgrade. Mr OP....not trying to derail your thread, but someone said .........t u r b o....:undecided: Wait, that was me. :cool:

There's a gent on inliners.org that runs a 2005 boosted with the factory PCM. If 2005 can do it, 2002 can do it.

If you guys can figure out what needs to be changed on the V8 PCMs to run in a I6 chassis, I'd be happy to program them for my standard price of $99.
 

smitty5150

Member
Nov 18, 2011
1,069
Thanks for the inliners heads up. I will check that out at some point today. Either way, looks like it is time for some more intense research. Hey, OP, thanks for bringing up the original question.
 

gmcman

Member
Dec 12, 2011
4,656
limequat said:
There's a gent on inliners.org that runs a 2005 boosted with the factory PCM. If 2005 can do it, 2002 can do it.

This is approaching the limit of my paygrade...but I believe the 02 ECM is different.
 

Jkust

Member
Dec 4, 2011
946
ScarabEpic22 said:
LS1 = 5.7L... :raspberry:

LS2 = 6.0L, like it but want more cubes for the SS. Make my 02 pretty fun though, but it'll have to get sold to pay for the built LS3 down the road.

Oops that's what I meant. I recall Marshal, PCM for less vendor, just posted a dyno sheet of a supercharged 5.3 with the efan and iirc both torque and hp were greater than a stock LS2.
 

ScarabEpic22

Member
Nov 20, 2011
728
smitty5150 said:
When I pull the trigger, rear will be swapped for an ss rear and I will convert to 2wd. I'm not looking to make a complete monster out of this, just a beefy dd that can handle the occasional track day. That, and the satisfaction of being the first known to do a swap without completely gutting and rewiring everything. I know there is the mentality that bigger is better, but I see no reason why a cammed 5.3 with a small supercharger(and a few bolt ons) wouldnt be sufficient. Add that to a slightly built 4l60 or 4l70 and I should be set. Since my drivetrain is 100% operational, I will be able to part it out to help offset costs.


I also would not mind running a turboed 4.2. Something I haven't looked into, though. Not sure how much more difficult that would be, though the benefit of keeping a lot of parts is slightly appealing.

Good idea, you could leave it 4WD if you wanted as the only part seeing the power on a daily basis would be the xfer case and they're pretty strong already. Shouldnt have to mess with the front driveshaft either, rear will have to be swapped/modified to work with the 9.5" rear though.

Heck even start with a cammed 5.3 setup for N/A then down the road swap cams and stick a Maggie on it. V8 cams are cheap ($400), but might have to do rockers/pushrods too (probably closer to $800-1000 for it all).

Turbo a 4.2, mmmm music to my ears.

gmcman said:
Oh, it would be most appealing....:biggrin:

Pull out the washer fluid reservoir and you could carry a baby kangaroo in there, all kinds of room for extra plumbing if needed.



Was it not a pita with the 02 ECM on retuning for forced induction...something like not allowing over 1 bar? Tell me it's doable and I may lose sleep.

If mine ever goes belly up that's what i'm going to try to do. Trans will be worked once it goes so the rear will be the next upgrade. Mr OP....not trying to derail your thread, but someone said .........t u r b o....:undecided: Wait, that was me. :cool:

Its doable...I figured out how to do it 2 different ways about 2 years ago, but never got a chance to actually test either theory (they're solid theories, but in practice who knows). The guy on the inliners forum used HPTuners to do it but EFILive would work as well. There are 2 ways, use a 2Bar MAP and halve the spark tables then trick the VE tables or leave the spark tables stock, run a voltage clamp on a 2Bar MAP so the PCM only sees 1Bar ever then run a rising rate FPR to increase fuel while in boost. Downfall with way #2 is you'll have a static spark value vs #1 you'll have spark control but only half the table resolution to do it in (and the 02-05 PCMs already have a much lower table res than 06-09s).

limequat said:
There's a gent on inliners.org that runs a 2005 boosted with the factory PCM. If 2005 can do it, 2002 can do it.

If you guys can figure out what needs to be changed on the V8 PCMs to run in a I6 chassis, I'd be happy to program them for my standard price of $99.

Good deal there, find an 03-04 TrailBlazer/Envoy LWB 5.3L OS and use that.

gmcman said:
This is approaching the limit of my paygrade...but I believe the 02 ECM is different.

Officially Ive heard they are a different part number and Westers made them seperate, however PCM4Less and everyone else the past 4 years has been swapping all year P10s without issue.


Seriously, turbo I6 or V8 swap, let me know. If you want to do a turbo I6, I have another trick up my sleeve for the PCM side of things Ive been wanting to try as well. Have all the parts, just need wiring and connectors (the expensive part lol).:cool:
 

gmcman

Member
Dec 12, 2011
4,656
ScarabEpic22 said:
Have all the parts, just need wiring and connectors (the expensive part lol).:cool:

You can use the wiring and connectors on mine....:thumbsup:

Tell ya.....when daycare is done....lookout.
 

ScarabEpic22

Member
Nov 20, 2011
728
gmcman said:
You can use the wiring and connectors on mine....:thumbsup:

Tell ya.....when daycare is done....lookout.

Need just the PCM connectors from an 06-07 I6, and ONLY those years (or 04-07 I4/I5 out a Colorado). Already have a P10 to test it on, and if my trucks in Montana with my brother Ill persuade Craig (FlyingFischer) to let me use his truck.
 

smitty5150

Member
Nov 18, 2011
1,069
ScarabEpic22 said:
Good idea, you could leave it 4WD if you wanted as the only part seeing the power on a daily basis would be the xfer case and they're pretty strong already. Shouldnt have to mess with the front driveshaft either, rear will have to be swapped/modified to work with the 9.5" rear though.

Heck even start with a cammed 5.3 setup for N/A then down the road swap cams and stick a Maggie on it. V8 cams are cheap ($400), but might have to do rockers/pushrods too (probably closer to $800-1000 for it all).

No fun in leaving it 4wd. I'd prefer 2wd, as I'll probably get an S series 4wd as a dd/parts hauler so I won't need it.Parts list looks like SS rear, SS 2wd driveshaft, 2wd tailshaft and tail housing, rebuild kit, shift kit, vette servos and actuators, exhaust, etc. Do a 5.3 built to handle a Maggie and leave N/A for now. Full exhaust and all the other little odds and ends. Gonna take time to get it all together, but parts shopping will be starting soon.
 

smitty5150

Member
Nov 18, 2011
1,069
5 min on EBay finds this in my area:
[EBAY]200689525518[/EBAY]
[EBAY]200701526400[/EBAY]

They include the PCM, engine harness, pedal assy, all accessories, and MAF. THIS makes me wish I was ready to buy now.
 

limequat

Member
Dec 8, 2011
520
ScarabEpic22 said:
Need just the PCM connectors from an 06-07 I6, and ONLY those years (or 04-07 I4/I5 out a Colorado). Already have a P10 to test it on, and if my trucks in Montana with my brother Ill persuade Craig (FlyingFischer) to let me use his truck.

I recently picked a PCM out of a saturn of some sort that appears to have 2 of the 3 connectors on a 2006 PCM. Might be a cheap source. I got the PCM and connectors for like $20.

Edit: just confirmed. The saturn connectors fit the 2006 PCM.
 

ScarabEpic22

Member
Nov 20, 2011
728
smitty5150 said:
5 min on EBay finds this in my area:
[EBAY]200689525518[/EBAY]
[EBAY]200701526400[/EBAY]

They include the PCM, engine harness, pedal assy, all accessories, and MAF. THIS makes me wish I was ready to buy now.

Nice finds, Id pick the LH6 because it has DOD (but if you're doing a cam swap it probably doesnt matter). But, the LH6 will NOT have a LS1B PCM, it will have an E40 ECM/T42 TCM. Would make the retrofit a lot harder as I dont know if GM changed BCMs and/or anything else for 05. Any 5.3L will work, just has to have a 24x crank reluctor and 1x cam reluctor (aka anything 00-04, fullsize til new body style in 07). Upside to buying a LM4 is that it will come with a factory TB OS, I havent seen one on EFILive's site yet, but I can probably ask someone to flash it off Tis2Web and then read it for me. And have the correct APP and TB too, plus it might have the factory fusebox plug. Pull the underhood fusebox, remove I6 wiring, replace with V8. Change some fuses and ready to go, no splicing in that case...


Edit: Crap that LM4 looks tempting, if I had $1300 (freight inc) Id be all over it and swap it into my 02 over the summer. The LM4 shows the correct PCM in the 2nd to last photo.

limequat said:
I recently picked a PCM out of a saturn of some sort that appears to have 2 of the 3 connectors on a 2006 PCM. Might be a cheap source. I got the PCM and connectors for like $20.

Edit: just confirmed. The saturn connectors fit the 2006 PCM.

Awesome news, eBay? I need all 3 connectors and all wires intact, if I need to move a few thats not a big deal, but Id like the majority of the wiring there (I can hope right?!). Saturn Ion Redline perhaps, they run a P12 too. Also I should be looking at LLY Duramaxes and E40 cars/trucks too.
 

limequat

Member
Dec 8, 2011
520
ScarabEpic22 said:
Awesome news, eBay? I need all 3 connectors and all wires intact, if I need to move a few thats not a big deal, but Id like the majority of the wiring there (I can hope right?!). Saturn Ion Redline perhaps, they run a P12 too. Also I should be looking at LLY Duramaxes and E40 cars/trucks too.

Erik, I have a local pick-n-pull that has great prices. I cut the engine harness about a foot past the PCM, and the only charged me for the PCM (I didn't want the PCM, I wanted the connectors). :smile:

So I just did a little more research. The car I found was a 2005+ Saturn Ion w/a 2.2 L61. These are ALL OVER the junkyards in my area. I walked past probably half a dozen of these cars. But that's not the good news, the good news is two fold:

1) The 2005+ Ions with the 2.0 have the same connectors as the 2006 4.2 - all three!
2) So do the cobalts!


Edit: This harness is way too expensive but you can see the 2 P12 style connectors. http://www.ebay.com/itm/05-COBALT-E...pt=Motors_Car_Truck_Parts_Accessories&vxp=mtr

So....who knows how to tell the difference between a 2.0 and 2.2 on sight?
 

gmcman

Member
Dec 12, 2011
4,656
As far as your options are concerned.....what about either fixing the 4.2 or picking up one from a junkyard, then sell yours and find a 5.3 truck?
 

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