It be easier and more cheaper just to build a carbed 350 with some ported L98 vette alumn heads, a good intake and carb and a healthy cam. Its going to cost a lot to convert your TBI ot TPI.

Bout the easiest way is to buy a TPI Painless Wiring Engine harness and get a TPI computer. Which is about $500 last I checked just for the harness. They also make the Lt1 harness for about $400.

Installing a l98 TPI motor is an easy enough swap, Id figured a few hundred dollars just to swap them out and transfer over all the accessiories and what not. A lot of money is going to be spend on converting it over.

Me honestly I would just buy a TPI car already or just do a carb. Im not very fond of Chevy wiring harness'