'80 305 carb/intake question

[deadllama]

I have an '80 C10 with a totally stock 305. It's got the factory Duojet carb, and only made 135hp when it was new. At some point I'm going to rebuild or replace this engine, but it runs fine, it's just slow.

I'd like to just run it as long as I can since it's original... but with that 2bbl and the little factory air cleaner, I'd like to help it breathe better.

If I were wanting to move to a 4-barrel carb, can I just find a good Quadrajet and bolt on a 350/Qjet intake? Are the 305/350 intakes interchangeable like that or do I need to go with something aftermarket?

Also, if I were to do that, what kind of effect would it have on fuel economy? (not that it's a big concern given that it'll be in the single digits either way)

Thanks y'all!

[Tom]

Yes everything from a 350 will bolt onto a 305.

[Dead Parrot]

If it still has the factory exhaust and converter setup, you probably won't gain much power assuming the current carb is in good condition. Especially if you still have the pellet filled pancake converter.

If your state has inspections, check the laws on swapping parts and keeping emissions equipment.

2nd on the easy swap ability of most SBC parts from one motor to another.

[68post]

I strongly agree with the above concerning the exhaust. Can you / have you run dual exh ? That and some lighter springs for quicker ignition advance can help a ton (& the 4bbl).

[deadllama]

Originally Posted by Dead Parrot

If it still has the factory exhaust and converter setup, you probably won't gain much power assuming the current carb is in good condition. Especially if you still have the pellet filled pancake converter.

If your state has inspections, check the laws on swapping parts and keeping emissions equipment.

I strongly agree with the above concerning the exhaust. Can you / have you run dual exh ? That and some lighter springs for quicker ignition advance can help a ton (& the 4bbl).

Should have mentioned, it's already got dual exhaust. Really old glasspacks... the fact that it's already got such a free flowing exhaust is why I think a 4bbl might help next. Good to know about the ignition advance, too.

[AcampoDave]

If you do swap manifolds, it might be nice to find a pre EGR version. That is of course provided that you can do that in your state. (In my state.....fuggetaboutit)

[deadllama]

Originally Posted by AcampoDave

If you do swap manifolds, it might be nice to find a pre EGR version. That is of course provided that you can do that in your state. (In my state.....fuggetaboutit)

Good point. I'm in TN, and it's got antique plates. Basically no holds barred.

[68post]

A good/used/cheap regular Edelbrock Performer would work slightly better than a stock intake if you find a deal.

[Wrenchbender Ret]

I agree. Find an aluminum intake for a Q-jet & use a Q-jet carb. If you are on a budget there have been a lot of 4 brl. aluminum intakes on SBC in the 1980 models. You can block off the EGR outlet. They are cheap at Swap meets. If you can O-haul a q-jet yourself you can buy them cheap at swap meets & such.
George