I did the typical lo3 to lo5 swap but im still unclear on what i need to do with my chip. I started the 350 fine on the 305 chip. But i read somewhere that using the 305 chip with 305 injectors on the 350 will lean it out but i have the 350 injectors. I got a police caprice 350 chip from a guy on craigslist and did some research and i believe the police tune uses bigger injectors and that will lean it out right? Someone please help i really would hate to blow my baby up. Do i need to use the 350 chip or the 305 chip? I dont have the means to tune yet and i have 2 back tires that need to die.

 

My advice would be to invest in a wide band O2 like the Innovative LC-1. It's cheap insurance when you don't know for sure.

 

I thought about that but which chip do i need to use?

 

I at least want to drive it down the street and roast em without detonation

 

Because of the way the ECM handles the injector flow to engine displacement ratio, both chips will be lean with the 305 injectors.

First put the 350 injectors in and see how it runs with the 305 PROM. Then swap to the 350 PROM and see how it is. It would be better if you had a way of scanning/data-logging to see what is going on in the ECM (knock counts, BLMs).

Which PROM would be better (305 vs 350) is hard to tell. The Caprice being a heavier vehicle usually has more conservative spark advance. You didn't mention which trans you have, but the TCC lockups will also be different between them (if the 305 is an auto).

RBob.

 

Whatever you do, don't go right out and rod on this motor. Not until you have the fuel trims and timing curve dialed in. Definitely error on the rich side to start with. And work your way back from there. Data logging or at least data monitoring is a very good idea.

 

This cannot be overstated, you have a lot of homework to do.

You will find that we will help, insofar that you help yourself.