ok so I’ve went through several 350 tbi engines so I’m trying to go ls can get a whole 6.0 and pcm and harness just I know I have to upgrade fuel pump but trying to figure the wiring head ache i can do the rest that’s nothing but the wiring is intimidating so any help new here

Melvin, if your not confident in the wiring process of these swaps, you can obtain a swap harness from an aftermarket company like speartech or PSI. They both (and there are others) make the process very simple, and can include a flashed pcm as well. As far as the fuel pump issue you mentioned, you can get a TI (Walbro) 255 that will drop right in your tank with out issue. You will have to regulate the pressure of course, and there are several ways to do that as well. Lots of info here on the site.

edit...oh yeah, and welcome to LS1Tech!