I've got a '00 or '01 complete 5.3 (i'm, pretty sure that what it is, any numbers on the engine I can use to verify that?) with the engine wiring harness and factory PCM. What would I have to do make this work in a 3/4 84 GMC? I would use the th400 trans that is in the truck now. I know there's more to it than just droping in it and putting 12 volts to it, but exactly what?

Can i use the factory PCM alone, or do I need a BCM to go with it? Or do I need to do a stand alone system?

 

Here is the link to the thread on my 79 C-10 swap
https://www.performancetrucks.net/fo...ight=79+Big+10

You can buy an adaptor for the flex plat to adapt to a TH400. You would want to send your harness and PCM off to be reworked. Speartech is good, Nelson is good, many places will do this for you. If you are good with understanding scematics, take it on your self, and find some one to tune your PCM so that it will run and perform well.
You don't need the 00 BCM at all.
All I can tell you is, research research research! Learn all you can and know what you want at the end.

 

You could search my username for threads I started. There's quite a few pages worth of stuff around this board on that type of swap. I think "montecarloSS" (don't remember exact username) has a few posts too. Use the advanced search option when searching. lots of info & pics!

BTW... my '86 is up for sale with the functional swap.