They are both the same motor other than the heads which you mentioned.

If your worried about the castech issue, just swaps heads and be done with it assuming the 243 heads aren't damaged in any way.

But it will be a basically plug and play swap. Everything should bolt in and plug in without any issues.

 

Thanks 19trax95!

From everything I had read and looked at I thought so about the plug and play swap.

Looks like flow is the same between the 243 heads and 706 heads so I may just swap them like you say and call it good.

 

One thing I do when I pull a motor (granted I work almost exclusively with diesel) is to label everything. And by everything I mean each plug, wire, and bolts. Sometimes I'll even take pictures.

I've found this takes a little longer on disassembly, but makes putting it all back together alot easier and less frustrating since everything is labeled and there's no guessing.

Like using zip lock bags for bolts and masking tape for wires/plugs.

 

I agree with that. I plan on labeling everything and taking pictures. Love my smartphone in the garage.

 

Good luck with the swap. If you run into any issues, post them up and I'm sure the community will he able to get them sorted out.

 

Thank you!

 

So I have a major concern now!

My engine is the L33 model with aluminum block. The Tahoe engine is cast iron block. Originally I was told this would work but now I am being told I need to change computer, sensors and more.

Any thoughts on this?

 

The L33 is the higher output 5.3. It has differnece pistons and a different cam.

But they should still swap. Can you take the pcm from the other motor too, or do you just have the motor?

 

I just have the motor. I planned to have a custom tune after the swap but wasn't sure whether my PCM would work or not now.

 

If your getting it tuned afterwards, just let them know what the deal is and it should be alright.

Although I can't say it as a fact, I can't see the sensors and all being different just because it has a higher power output. It's not flex fuel or anything, just a regular 5.3 that has flat top pistons and a different cam

 

Alright. Kind of what I was thinking but like I said I know nothing about the electronics!