Hey I just got a 91 rs (we need it to test fit our new ram air camaro hood on) It has a new factory GM 350 motor in it (12000 miles) The guy I got it from said it had a 305. When he put the 350 in he used the 305 intake and throttle body and it never ran right. It runs ok good power but it sounds like it surges at a steady speed and it gets BAD gas milage. Would having the 305 stuff on it be a bad thing?? also if I went with a intake and 4 barrel would this make a diffrence in milage?? What would have to be done to put a carb on this?? also what size would be good??
Thanks,
GT Auto Acc www.geocities.com/gtautoacc

 

get a 350 knock sensor and new O2 sensor first.

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-Tas
'89 Formula WS-6

305, TBI, auto, 14x3 chrome flat based open element with K&N, Milodon 160* thermo, functional Formula hood, cross-flow Flowmaster, '99z28 rear pipes and tips....

Soon to be installed:
Hooker 1-5/8" 50 state legal headers, Dynomax 3" I pipe (PN 44063 and 43248), Catco 3" cat, and injector spacer.

Super GRK_Taz World
F-Body Dual Exaust
EFI & Intake Options
AOL IM: superGRtaz

 

Is this the only diffrence between the 305 and 350?? I will give it a try

 

Did the guy swap to 350 injectors? With a 350 knock sensor and the 350 injectors it should run decent depening on which new 350 engine he put in it. After that a chip should help a lot. Maybe he left a vacuum leak or some other simple thing like that when he did the swap.

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1989 Pontiac Firebird Formula LO3 Auto
-180 degree stat
-Hooker Cat-Back
-velcro t-top bag
-Wonder Bar from my IROC
*****Possible future mods*****
4th gen seats, fiberglass spoiler, new paint

1985 IROC-Z, TPI Auto
-Accel Super Coil
engine and tranny overhauls coming this summer


http://www.geocities.com/krt80/

 

If it's running 40 injectors and a stock chip then you are going to have problems. Get more details for us and we should be able to figure out your problem.

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, Jon (350 TBI!)
91 Red My website

 

Every thing from the heads up is off the 305. He said he got a long block from GM and put everything from the 305 on it. I also have a 88 TA 305 tpi that gets twice as much fule milage then the Camaro is this normal.

 

You should get at least in the low 20's in fuel mileage. As fare as the ruff running I'm with the others in saying that you should change your o2 sensor and find some larger injectors. If you have a good boneyard near you, you could pick up a set of injectors and a chip or ecm out of a caprice that had a 350tbi in it. I'd say that would solve a lot of your problems.

Steve