I have a 91 305 TPI, it came with the dual cats, now has the Hooker 2055's and 3" exhaust...

I need to replace the fuel injectors... I got a ported plenum (which I will use), and I am purchasing AS&M runners & Edelbrock Base (which I want for a future 383)...

While I'm getting into replacing the injectors, should I replace the base and runners or would the 305 suffer?

It does have the same cam the 350's had in 91 and 92, and I can tune the car, EBL P4... Stock heads...

Just wondering... If not, I'll just use the ported plenum and save the runners / base for the 383...

Thanks,

Rafael

 

With a mostly stock 305 and putting on the high-flow base and long-tube runners, I have personally seen either zero gain, or approximately 10 HP gain depending on specifics of the install and the particular tune.

I have yet to see a power loss from adding these parts, but I'm sure some people out there have managed it.

It may turn out the you notice more gain or loss from your injector install than with adding the high-flow intake parts.

If you port match everything and block off the exhaust (EGR ports) from the heads to the intake, then you are sure to get a small but noticeable gain.
I wouldn't expect anything big though. If your heads are stock/untouched, then that's where most of your restriction is right now, specifically in the bowl areas around the valve-seats.
Once the heads can flow more, then the high-flow base & runners will earn their keep, even on a 305.

 

I wouldn't wast your time swapping it out on a 305.