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[dliving69]

So I gOt a 78 305v8.. Was looking into getting a new intake and carb. What dO I need to do to add a four barrel intake and carb?? Any help please!
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[Stricklinator]

Did it come with a two-barrel? My truck with 307 came with a leaky 2-barrel and I have never rebuilt a carb, so I just bought a intake/carb/air cleaner combo from Summit Racing. It came with a nice looking aluminum intake and a brand new 600cfm (Holly style?) carb with electric choke and a chrome air cleaner. I put it all on and it fired right up with no adjustments needed right out of the box. IIRC it was $234. I am sure their are junkyard swaps you can do to, but I don't know the specifics.

Paul
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[68Gold/white]

Originally Posted by dliving69

So I gOt a 78 305v8.. Was looking into getting a new intake and carb. What dO I need to do to add a four barrel intake and carb?? Any help please!
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Ton's of 305's cam w/ 4 Bbl's. But be careful what you buy. Most aftermarket intakes are not the best thing for a 305. If you don't have emissions tests to worry about, I'd look for a 70-72 iron stock Q-jet intake. A Q-Jet off a 77-81 Chevrolet engine can be made to function w/ your engine. It would be nice if it was off a 305, the secondaries will already have the proper opening (wide open) for the 305. Look for a tiny circle at the front of the carb, on top, where the air cleaner gasket sits. This identifies the carb as an APT carb. It's the best Q-Jet for most purposes. If you need parts go to www.Cliffshighperformance.com , his parts are compatible w/ todays gas that has methanol in it. and get his Q-Jet book, also.....

You can find the carb for around $10-20.00, and the intake for around the same $$$

You may need a different throttle cable bracket and other parts, they can usually be found, easy enough at a salvage...

[dliving69]

Originally Posted by Stricklinator

Did it come with a two-barrel? My truck with 307 came with a leaky 2-barrel and I have never rebuilt a carb, so I just bought a intake/carb/air cleaner combo from Summit Racing. It came with a nice looking aluminum intake and a brand new 600cfm (Holly style?) carb with electric choke and a chrome air cleaner. I put it all on and it fired right up with no adjustments needed right out of the box. IIRC it was $234. I am sure their are junkyard swaps you can do to, but I don't know the specifics.

Paul
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No it came orgianaly with I beleive its a 2 barrel. and It leaks..but i found a deal on a four barrel intake and carb and was debating on upgrading or just rebulding my carb

[Stricklinator]

You might want to find out how many cfm you need for your engine size. I think the 600cfm 4-barrel on my 307 is a tad too big. I was planning on getting a 350 long block at some point, so I figured I could just swap my parts over to the bigger engine then and it would be perfect. If your keeping the 305, you might be better off with a 2-barrel, but I'm not sure. It sounds like 68Gold/white knows these engines/carbs pretty well, maybe he can tell you which would work better.
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[Daves70]

How do you drive your truck? The reason why I ask is a q jet equiped 305 is incredible on fuel if you can stay out of it and keep the rpm's down on the road,but if you are standing on the gas pedal all the time you will be better of with the two barrel.A four barrel will give it a little more power though.If you are changing for performance then there are way better engine choices for our heavy high drag trucks.

[dliving69]

I want power, I am on the gas a bit

[Daves70]

Originally Posted by dliving69

I want power, I am on the gas a bit

Then I would get a 600cfm carb and use that. Then you have a good carb for your future 355 or 383 or even a 400 build.305's are great fuel mizers but they don't make enough torque for these trucks for performance imo.You can build or buy a decent 350-400 hp 350 for relitively cheap now and I think you will enjoy the truck more that way.You know the old saying there is no replacement for displacement.Again IMO.

[dliving69]

Can you get a 600cfm carb 2 barrel or are they just in 4? I am still learning all there is to know about engines and such..??what about an adapter to allow a 4 barrel on a 2 barrel intake? Good or bad?

[MARKDTN]

I would go to the junkyard and find a late 70s to mid 80s 305 Caprice, truck, or Van and get the aluminum intake and q-jet. Should be able to find one with a 305 pretty easy. As long as the center 2 intake bolts on each side are not straight up and down, it will fit. Change to HEI distributor while it is apart. The Q-jet is a kind of best-of-both-worlds item with small primaries for economy and big secondaries for power. It is a very misunderstood carburetor. It must be rebuilt correctly or you will have problems and will rename it "quadrajunk" or "quadrabog", but when they are working right, they really shine.

[stsalvage]

well if you have a 305 best carb is the 500 cfm but the 600 will work you can detune the carb and change the jetting in it this is what your after in the pictures

[dliving69]

Thanks for all the help. Any good ideas for a new intake and carb? Where to get them with a good deal? its 78 305

[dliving69]

How can I get better throttle response from my 78 305 stock setup with the qjet? and what is my stock carb?