77 big10 roller 5.3 LS swap

[Gonzalo_3]

This is my first LS swap ever on a 77 big 10 Silverado. I found this truck in a field and its just a roller. I feel confident about the swap, however I just wanted to run some stuff by this forum to see if y'all have anything to say about my plan. I have a donor truck (2004 Yukon) and I plan on using the engine and engine wiring harness out of the donor. I will need a new body harness to wire everything back up. Another concern of mine would be mating a Th350 and making sure I have the correct engine mounts, transmission crossmember for a solid power train. My main concerns are with the mating of the LS and TH as well as the chassis wiring. Like I said this is my first swap and I'm looking for some help with my "pre swap thoughts". Thanks

 

[CountKrunk]

Does the donor truck not also have a trans?

 

[Edelbrock]

Ya, like he said - I would try to keep the LS engine with the "LS" trans, for several reasons.