I just saw a complete tbi set-up on ebay for @ $500. I think It came off an 89 engine. For starters-
You have to install the throttle bodies in place of the carburetor, of course.
You have to install another intake manifold set up for throttle body.
You have to remove the mechanical fuel pump, install a block-off plate over the hole and install an electric fuel pump usually inside the fuel tank(s).
You have to install an ecm that works with throttle body application.
You have to run wiring between fuel tank, throttle bodies, transmission, and ecm.
You have to install a new throttle cable and bracket.
hmm, there's something else and I forget what it is- maybe the vacuum advance..
Don St.Clair
Culleoka Tn