9-7x 4.2 to 5.3 Swap

Maverick6587

Original poster
Member
Dec 16, 2018
730
Sterling Heights, Michigan
After about 20 days of trying to talk myself out of it... I decided to pull a 5.3 out of an 07 9-7x from a local you-pull-it.

The mileage was not listed on the vehicle. However on the oil change sticker on the window said, next oil change at 4,110 miles and the oil change sticker was almost 2 years old. I find it very hard to believe that an 07 only had 4k miles on it 2 years ago.

I ran a history report and found that in 2014 it had 94k miles on it for the sale of the vehicle. Hopefully, it has less than 200k on it now.

Anyway, I plan on doing a complete rebuild of the engine and putting that into my 06 9-7x (unless I can find a cheap newer 9-7x to put that 5.3 into). I was doing a search to find the reluctor count on my 4.2 and I just cannot seem to find it anywhere. I know that the 07 5.3 has the 58x relcutor and I assume mine has the 24x reluctor. If the reluctor is different than mine, do I just need to be careful on the ECM I use for the 5.3? I have a tech 2, so I assume I could reprogram any 07-09 5.3 ECM to work?

I did find this great chart for GM reluctors! They just don't list the 4.2 version for gmt360.

All I grabbed from the 07 5.3 was the engine (with all accessories) and the wiring harness. I'll grab the TCM and ECM (and probably the entire vehicle wiring harness) from an 07+ 5.3 at the junkyard later on. Someone had already grabbed the transmission before me. I assumed they planned on grabbing the engine as well as they cut the exhaust and some of the wiring harnesses near the engine. Maybe they saw something that looked like the engine wouldn't run and decided not to take it or they didn't have enough money for both pieces... I don't know. I didn't care though, as I plan to completely rebuild it.

There was no big oil leak and the coolant looked very clear with the red coloring like it had just come out of the coolant bottle.

This was me and my dad's first engine pull from a junkyard and there was a slight learning curve. It took us about 6 hours to pull the engine. For anyone else who has not pulled one from a junkyard but thinks that they might want to... Here are the key points to take away from my first go...

1. Bring about 3 fully charged batteries with whatever brand reciprocating saw you own
a. We ran out of juice. We needed one more battery and we could have gotten it out a day earlier.
2. Cut the exhaust pipe above the flange near the engine
3. Remove the exhaust manifold heat shield
4. Cut the sway bar links and the very bottom of the front shocks
a. Cutting the shock at the bottom so you don't have to try to remove it from the yoke. There is no pressure at the bottom of the shock.
5. Leave at least one engine mount bracket bolt in place on each side
a. The engine has two cross members underneath it, so It won't fall if you forget to leave a bolt in place on each side
6. When you are trying to lift the engine out make sure you lock your hook near the front of the engine, to lift it up on an angle.
a. You need to use some brute force and shake the engine forward and backward, to get the engine mounts loose from the frame.


Steps that are not necessary but, would make the fight of getting the engine out very easy. Especially if you are pulling the transmission out while still attached to the engine.

1. Remove or cut out the front bumper
2. Once you have the engine weight on the hoist/come along, cut out the cross member

Anyway, that engine pull was actually a lot of fun and I plan on doing it again. Hopefully, this inspires someone else to get a little dirty and pull a used engine.

IMG_20191123_130350.jpgIMG_20191124_110641.jpgIMG_20191124_122134.jpgIMG_20191124_125226.jpgIMG_20191123_123533.jpgIMG_20191123_143736.jpg
 

Mooseman

Moderator
Dec 4, 2011
25,262
Ottawa, ON
Cool beans!

For the tranny, you can keep yours. Just have to replace the bellhousing and torque converter.

Did you grab the driveshafts? IIRC, the tranny position changes with the V8 but I may be wrong. There is also the rear diff with the 8.6 ring gear (and 3.73) that you would need as the current 8.0 will not survive long behind a V8. And if you do that, you'll need the front 3.73 diff if yours isn't that same gear. Hope you also got the engine mount brackets.

You will definitely need the PCM and TCM as well as the entire wiring harness. Not sure how it will tie in to the rest of the truck's current body harness. You don't really need the reluctor count of the 4.2 since it's being replaced anyway.

I'd go to a non-DOD cam and lifters. Don't need to deal with that BS. Are you planning on putting in something a little peppier?
 

Maverick6587

Original poster
Member
Dec 16, 2018
730
Sterling Heights, Michigan
A thought/idea I had was to grab a 4L80 and the axle out of an SS. That way I can swap a 6.0 in there IF I ever even see one.

The driveshaft is just sitting there. I'm not too worried about that at this point though. I can grab all the accessories later on. Good to know about the diff though! I would not have even though it was different than the 4.2. I plan on doing a non-DOD and putting in at least a bigger cam and replacing everything internally. I haven't decided how much HP I want/need out of the engine yet.

It looks like I can for sure get 700 HP out of it. If I can find a way to do that for under $2k then that will be the rat rod's engine... If not, then it'll be a 500 HP (hopefull) DD for me.
 
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Mooseman

Moderator
Dec 4, 2011
25,262
Ottawa, ON
If you're gonna be making 500hp minimum, you will need that SS diff. Even the 8.6 won't survive behind that.

Looks like a nice project for sure!
 
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Maverick6587

Original poster
Member
Dec 16, 2018
730
Sterling Heights, Michigan
Looks like the diff is still attached to the 5.3 engine. If I can't find a front diff on an SS, I'll just go RWD at least as a starting point.
 

Mooseman

Moderator
Dec 4, 2011
25,262
Ottawa, ON
The front diffs are all the same. Just the gearing is different. If you're going for an SS rear, you can pick any GMT360 front diff with 4.10 gears.
 
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Maverick6587

Original poster
Member
Dec 16, 2018
730
Sterling Heights, Michigan
Pulled the spark plugs yesterday. They actually look decent... Besides the red headed stepchild. They are shown in order. The top left-hand spark plug is left rear of the engine (cylinder 8).

The engine was slightly tilted to the left (as it's sitting on a dolly right now) and there was a fuel smell only coming from left side of the entire spark plugs.

I'll be purchasing an engine stand tomorrow, hoping to find a black Friday deal though. I already found a 1,000 lb stands for $49 at HF.

Does anyone see anything that stands out from the spark plugs? The right side (toward you) has sone build up on them that I'm not familiar with.

IMG_20191127_170214.jpg
 

Mooseman

Moderator
Dec 4, 2011
25,262
Ottawa, ON
The two bottom middle ones look like they have a lot of thick soot. All look worn out as the iridium tips are mostly gone. That part number on the ACDelcos are the originals from the factory so they were never replaced.

If you can, try to get a compression test done before taking it apart, unless you really don't care since you're rebuilding it anyway.

Don't you just hate a half-assed job of just replacing one spark plug? If that's the case, this engine may have been poorly maintained. What does it look like inside, oil change wise?
 
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Maverick6587

Original poster
Member
Dec 16, 2018
730
Sterling Heights, Michigan
That's all we had time for... I really wanted to see the plugs condition and spray some Marvel Mystery oil into the cylinders, since it'll be sitting for a month or two.

I will be taking into to be machined. It's current condition is not catastrophic (afaik). I'm hopeful that some parts (the few) will be reusable at some point, even after the overall.

I will do a compression test though. I'd love to know the current condition of the valves and cylinder walls/rings. Either this weekend or next will be the compression tests.
 

Maverick6587

Original poster
Member
Dec 16, 2018
730
Sterling Heights, Michigan
@Hobbyist4Life This build is still up in the air as to whether I'll be putting the 5.3 in my DD or in the ratrod. I have a guy I'm working on swapping engines with right now. The 5.3 for a 6.0 LS2 already built for racing (not used) for $1k. If I can pull that off, then the 6.0 is going into the ratrod.

Otherwise, it's looking like the 5.3 will be going into my DD with a 6L80 trans (with a few adapters and other components).

Edit: I'm not afraid to take apart that already built engine just to inspect and verify parts that were replaced and what brand was used. I would definitely have the heads and block inspected for alignment. If I get the engine, I'll probably add top fuel hoops to the heads and block.
 
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Maverick6587

Original poster
Member
Dec 16, 2018
730
Sterling Heights, Michigan
I only have a few months or so to figure mine out though. I need that ratrod race-ready by august next year. Time is ticking... I just need to hear an engine running on a frame at this point to settle down the anxiety. :salivate:
 
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