I just finished installing TBI on my 1986 C20-454 with GM in tank fuel pumps "2 tanks"
Before you go through all the trouble of striping the old harness and sensors check these guys out www.affordable-fuel-injection.com
They sell wiring harness,complete kits,and just about anything you'll need for the conversion
hope this helps
good luck

Some people are like Slinkies, Their not really good for nothing... But they still bring a smile to your face when you push them down the stairs.

1951 3100 350 TBI Gallery Toddzilla... "$old"