305 to 350
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Joined: Feb 2006
Posts: 8
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From: Camanche IA
Car: 89 Formula
Engine: supposed 350
Transmission: 700R4
305 to 350
Hey to every one out there in 3rd gen land. I have a 89 Fourmula that started out life as a 305. I was told by the man that sold it to me that he blew the engine up and that the car now has a Z71 4bolt main 350 in it.(yes i know thats a chevy going in to a pontiac i was told that there was no way, then was told that it was easy to do ) By the way im a ford man going GM so be gentle on me. lol
Problem is i was told that the computer that was running the 305 is the same one that is now running the 350.
I have been told that this is bogus info then was told it would work fine then was told that it would work but it would be better to get a true 350 computer. Im only asking cause im planing on putting a new LT1 H.O. in my car and im wondering what all im gonna end up needing. Oh i think i have a TPI set up on my engine, to me it looks like a carburater that is modernized
Problem is i was told that the computer that was running the 305 is the same one that is now running the 350.
I have been told that this is bogus info then was told it would work fine then was told that it would work but it would be better to get a true 350 computer. Im only asking cause im planing on putting a new LT1 H.O. in my car and im wondering what all im gonna end up needing. Oh i think i have a TPI set up on my engine, to me it looks like a carburater that is modernized
Joined: Mar 2000
Posts: 43,187
Likes: 42
From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
Welcome to the kingdom of 3rd gens. 
Sounds like a TBI engine. From a Z71, that's very likely.
Most likely it would benefit from some "tuning", and that means the PROM (chip) in the computer. The "best" long-term approach is to get the equipment and learn how to burn your own programing. 2nd best is to get a PROM for a 350 (which our cars never had with TBI).
Check out the TBI forum for more info.
However. . .
If you can live with the way it runs now, the LT1 will require a whole new computer and "solve" the problem for you.

Sounds like a TBI engine. From a Z71, that's very likely.
Most likely it would benefit from some "tuning", and that means the PROM (chip) in the computer. The "best" long-term approach is to get the equipment and learn how to burn your own programing. 2nd best is to get a PROM for a 350 (which our cars never had with TBI).
Check out the TBI forum for more info.
However. . .
If you can live with the way it runs now, the LT1 will require a whole new computer and "solve" the problem for you.
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