I have a 02 trailblazer and doing a ls swap. I need to know the pinout for the one plug that controls everything in the inside on the 4.2.. the 5.3 plug is different. And the 5.3 motor is a 07.. the plug is by the fuse box and goes in the firewall to the inside of the trailblazer

 

That about as vague of a comment as I've ever heard. I'm sure there is more than one plug but I would do yourself a favor and just sell your TB with the 4.2 and buy one that had a 5.3 in it. This swap is NOT worth it almost anyone on here will tell you that. The oil pan alone is around $400 for this swap not to mention the wiring headaches, sourcing the V8 bellhousing, integration, programming blah blah blah... Just buy the V8! Good luck.

 

I have to agree. He's glutten for punishment.