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I have a 58-62 corvette engine that is original except for the carburetor. I would like to put an intake and carburetor better for everyday driving in my 58 corvette. Any suggestions for a setup that will fit under the hood.
Thanks you for your response. The intake is a 3746829 and the carburetor is a Rochester. I had to put a wood spacer in to prevent vapor lock, because this intake heats the carburetor with exhaust air. The engine also hesitates with acceleration after the choke is off.
I can't imagine any Rochester carburetor that will fit that intake manifold and function properly; the pad on that intake, throttle bore holes, and bolt pattern will only accept a Carter WCFB. It's a good idea to plug the one exhaust heat passage on each side of the carb pad below the carb baseplate too.
You need to do 2 things. First, as Roy mentioned, block the heat crossover passage in the manifold. The easiest way to do this is to use intake manifold gaskets with blocked passages; you need to change the gasket anyway when you have the manifold off. These were used on many later small blocks and an auto parts store ought to be able to help you come up with a set. I MUCH prefer the type with a stainless steel plate blocking the heat crossover passage to the type that simply have gasket material blocking the cross-over. Exhaust heat will degrade the gasket material rather quickly; the stainless steel plate will last the life of the gasket.
Next, you have to eliminate or wire open the heat riser valve. You cannot use a blocked cross-over with an operating heat riser valve. I recommend eliminating the heat riser entirely------that way there's no chance that it will ever become inadvertantly operational. To eliminate the heat riser, install a spacer (as was used for FI cars and as available in reproduction). Alternately, you can remove the valve and carefully "excise" the butterfly valve. I prefer the spacer; it permanently eliminates the oft-experienced "rattling" of heat riser valve.
Following the above 2 steps, your manifold and Rochester 4 GC carburetor should work perfectly.
John's correct; I don't know what I was thinking of when I said Rochester 4 GC. Your car original used a Carter WCFB and that's what will fit your manifold.
Has my memorey failed me? Some '58 pass cars used the 4GC Rochestor and '58 Vettes used the WCFB Carter. Manifold won't support either installation? What's different in the overall installation other than the carb base gasket,
the different routing on the fuel line and the choke clean air tube? I'm curious.
Yes, you're correct. So, I was "half correct" to begin with. These early 4 barrel manifolds will fit either WCFB or 4GC. Corvettes never used the 4GC, though. The first use of a Rochester carburetor on a Corvette was 1968.
Well, that dates me, I guess; I've never seen a Rochester 4GC except in photos in really old shop manuals. Can't imagine the 4GC working very well with the manifold, as the 4GC throttle bores are 1-5/16" (per the '57 passenger car shop manual) and the WCFB throttle bores (and holes in the pad) are all 1-1/8".
I recall them from my days of working in a service station during the 63-65 period. They were common on GM pasenger cars with 4 barrels and I saw a lot more of those than Corvettes. A good friend of mine (one of the people that most influenced me getting into cars)used to have a bunch of them around, too, as I recall. He was always scrounging parts and these things were pretty easy to scrounge, even then. To be honest, I always, even to this day, confused the 4GC with the WCFB even though they are compeletely different carburetors.
GM says that the manifolds for both the 4GC and the WCFB were the same. Originally GM PART #3750511 and, later, GM PART #3852568. I would not rule out the possibility that the same manifold casting, machined differently for 4 GC and WCFB applications, was used in PRODUCTION and, one or the other, used in SERVICE as a one-size-fits-both. I greatly doubt it, though.
The hot set up as I remember it was to use the '58 Buick 4GC on the stock Chevy manifold instead of the Chevy 4GC because of the bigger bores. Maybe they used several gaskets to jack the carb up so the throttle plates would open. I don't know. Never did it.
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