I have a 87 trans am gta. Stock 350tpi is no more.
Now i have a 94 lt1 9c1 engine whit 4l60e transmission, ecm and eletrical harness.

Anyone spliced the harness into the car and can give a litle bit of help what to do!?

 

Lots of threads on this, I had never done this before when I swapped my lt1 (project zzzzzz). I read someone said it would take 2-3 hours to do the harness...for me it was much much much longer than that. There is a reason that the harnesses are several hundreds of dollars to purchase, but in the end I'm proud of what I accomplished and learnt lots in the process which partially why I do it. I utilized probably 3 or 4 documents online mostly but took little bits from many more to figure out certain things. Take your time and just start with The first wire and work your way down the list. Also it worked well for me to just hack it to get it working the go back and redo everything after I knew it worked. If you check out my swap thread I have a before and after pic that illustrate how messy it was at first.