i have a 1986 iroc-z 305ci TPI LB9 and I want to put in a 350TPI, am I going to need to switch computers? and are there any other parts i will have to replace to put that in? http://www.gmpartsdepot.com/store/pr...&Category_ID=2

 

as far as I know you have to get a new chip. Are you swaping any of the parts from the 305 over to the 350? If so the fuel injectors and the throttle body are going to be to small for the 350.

 

I did a 305TPI to 383 SUerRam swap last summer in my 91 Formula. Everything wiring wise will fit just fine since you're going from one TPI to another. Just reuse your existing sensors if the 350 doesn't come with them. I probably would anyway (use the old sensors) just to make sure I didn't introduce any possible new variables (at least at first).

The only exceptions to this are:

- the fuel injectors (you'll need 22's instead of the stock 19's on your 305)

- the knock sensor (you'll need one for a 350)

- the computer memcal ("chip"). You need the whole memcal, not just a reprogrammed chip. That way you get the correct knock and limp home mode circuitry. They're avaialble through GM Parts Direct for something like $50.

Since you're going from a small block TPI set up to another small block TPI setup, this is actually a very easy swap as engine swaps go. Good Luck!

- Vern