Recently i bought a 1998 full size with a blown 4,3vortec and 5 speed manual. I am going to put my 1990 350 TBI into it. I know the motor will drop right in. I assume zi will have to change puter and engine harness. Can i disconnect at fuse block under hood and hook up TBI engine harness there or will i have to change from computer all the way through the fire wall to the engine. My TBI has been recently rebuilt and dont want to change that. Thanks for any replies.

 

I'm guessing you'll have to change out the whole harness that goes through the firewall up to the ECM. I don't know how the 98 cluster will interact with the old computer but I'm sure you can get it to work.

I'm thinking your 90' ECM will have to be for a manual trans, because the regular automatic transmission has provisions for the TC lockup. So you'll need a TBI w/manual trans ECM, but other than that I'm not thinking of any issues ...

I've never done this before, but sounds like a promising project! Good luck