4L60E full transmission swap, what a mess......

[NaGall]

Back in March of this year, while driving on one of the major business loops here in San Antonio's West side, my transmission decided to detonate 2nd and 3rd gear, self destructing in the middle of an interchange ramp. Fast forward to July, and I finally got the transmission swapped, post-install inspection completed by my local service shop, and am back on the road. Unfortunately, I have something new to deal with.
While the shop had the Trailblazer, as part of their inspection, they were test driving it and shortly after they got on the road, my main drive shaft literally fell off. Come to find out, the u-joints I was sold from O'Reilly Auto were the wrong style u-joints. All they did was install the correct style and remount the driveshaft. They did not inspect the driveline for damage, or any other components that were bashed and smashed by the spinning drive shaft. I now have knocking, creaking, and metal striking/grinding on metal sounds emanating from the rear end of my little red Chevy.
To top it off, I also have a undiagnosed fluid leak that I can't seem to trace and I am worried I may be looking at an impending engine rebuild or complete block swap in the near future. Now that I have the backstory covered, here are my questions:

1) I do not want to do a straight 4.2L block swap if I have to replace my engine. I would like to find out if anyone has done a 4.8L V8 or 5.3L V8 swap and, in particular, what all needed to be changed to get it to work?

2) Has anyone done a diesel swap to one of the following diesels: either a Gen1/2 or a LBZ Duramax, a Turbo Cummings, or a 4BT Ford?
2b) If so, how difficult/costly was it?

3) Would the stock 4L60E transmission work on and of the GM engines I've listed above?
3b) If not, what transmission should I look for that will fit under my body of my 2003 Trailblazer LTZ?

Thank you in advance, especially for keeping the sarcasm and snark to a minimum. I already get it that with enough money, I can do anything. I'm just asking if anyone has already gone down this rabbit hole and what they encountered before I start the trip.

 

[Mooseman]

1) I do not want to do a straight 4.2L block swap if I have to replace my engine. I would like to find out if anyone has done a 4.8L V8 or 5.3L V8 swap and, in particular, what all needed to be changed to get it to work?

You practically need a whole 5.3L donor truck. Even the rear diff and driveshaft need to be swapped. Only a couple of guys have done it.

2) Has anyone done a diesel swap to one of the following diesels: either a Gen1/2 or a LBZ Duramax, a Turbo Cummings, or a 4BT Ford?
2b) If so, how difficult/costly was it?

Not that I know of. You would need to find a TBSS rear diff as that's the only one that may have a chance of surviving behind that much torque and those came only with 4.10 gears. Forget about trying to keep the front diff with such a swap if you have 4x4. I don't think there's any front spring available that could hold up that much weight.

3) Would the stock 4L60E transmission work on and of the GM engines I've listed above?
3b) If not, what transmission should I look for that will fit under my body of my 2003 Trailblazer LTZ?

Not behind anything bigger than the 5.3L. The TBSS (6.0 LS2) was mated to a 4L70E

 

[TheHoogyMan]

1) I do not want to do a straight 4.2L block swap if I have to replace my engine. I would like to find out if anyone has done a 4.8L V8 or 5.3L V8 swap and, in particular, what all needed to be changed to get it to work?

You practically need a whole 5.3L donor truck. Even the rear diff and driveshaft need to be swapped. Only a couple of guys have done it.

Late to the conversation here, but I've completed the swap and I figured I'd share in case you or others would like more information- '07 Trailblazer with full interior and drivetrain swap from '06 9-7x 5.3i. It came out as if it were factory and I'm very happy with it, although with 2 post lift and separating the body it was still a considerable project. As Mooseman said, A donor truck is HIGHLY recommended (but I cannot recommend taking on a project like this to most people).

Just to get the V8 sitting in an I6 frame and wired to the other systems you need to:

1. Obviously need to find an engine, harness, ECM/TCM and mounts, GMT360 oil pan, etc. etc. 2WD vehicles can use the C6 Corvette pan when using aftermarket bracing (LC32 makes a kit). Too many variables to cover here with just the engine selection alone, that could be an entirely new thread.

2. V8 engine side and frame side brackets, as well as isolators. There are aftermarket solutions that eliminate the factory brackets, or at least one option that swaps the factory isolators in favor of poly mounts.

3. Then comes GMT360 specific exhaust manifolds and y pipe/cats are a must (or header kit, only a few options available) as full-size truck exhaust doesn't work. I cannot say for sure that the I6 exhaust will not bolt up to V8 location, I didn't try.

4. Transmission bell housing are different between 4.2 and V8, but they can be swapped. T50+ bit (if I remember right) and some heat to get the bolts out.

5. The 4.2 frame requires the transmission crossmember mounts to be cut and welded about 2 5/8" forward. Or have a crossmember fabricated.

6. Switch to a V8 under hood fuse block and IP harness, which runs from the engine bay to the rear seat fuse block. Avoid mixing years and options when it comes to electrical, pinouts take forever to compare. It is possible to change pins in part of the V8 engine harness to keep the original fuse block and then convert a I6 IP harness, but it very, very time consuming and looks horrible if you aren't crimping terminals and pinning a new connector. Much of the interior has to come out and the dash completely torn apart to run this harness.

More differences that I can remember between I6 and V8: (most likely forgetting numerous things)
- fuel and transmission lines
- AC compressor, condenser, and lines
- radiator, hoses, heater hoses, fan shroud
- steering pump and lines
- driveshaft(s)
- V8 washer reservoir and air box lid (5.3 and 6.0 are different)

 

[mrrsm]

Splendid approach and a Superb Write-Up... Any chance for having "Candles On The Cake"...via some more Photos?

 

[TheHoogyMan]

I feel like I'm hijacking here haha.

Unfortunately I had Google's auto cleanup enabled when I first got my new phone back then and it deleted a bunch of photos from the early stages, but I'll post a few that I still have. I still need to get the SS bumper repainted and swapped, as well as install the other hood. I was thinking of putting hood louvers from a third gen Camaro in the old hood, hence the dry erase marker in one of the pictures, as it would be nice to figure out an aesthetically pleasing way to get some heat out of the engine bay.

93k miles drivetrain, refreshed the 5.3 with new bearings/rings and had the reads refreshed and milled .010. I installed a Truck Norris NSR cam and Delphi lifters, LS1 Camaro electric fans, used the I6 VJCX converter, Belltech drop kit with rear airbag/compressor setup from the Saab, drivetrain is AWD with 8.6 rear and 3.73 gear (have a 9.5 4.10 rear as well, just need to find a matching front diff if I ever decided to go that route). Not 100% finished but I haven't been able to find nice black/ebony silk plastics.