I have an SBC engine which I believe is a 1993 350 4 bolt that came with fuel injection. What is the best way to convert it to carburation? Should I get an intake manifold and if so which one, or is there an adapter that allows mounting perhaps a 2 barrel carb onto the original intake for the F.I.? Any suggestions? As you know, this is a later engine with 4 bolt valve covers and I believe vertical bolts at the middle position along the sides of the intake manifold. Also, I believe the engine is pre-vortec, but many of you know this stuff right off the tops of your heads, so suggestions welcome. Thanks in advance. Pictured is the project in which this will run.
If it has intake bolts that go in at an angle it should use any early Chevy intake.If they go straight down its a Vortex.They do make intakes for Vortex type engines that take a 4 barrel.Does your engine have a block mounted fuel pump? At some point they stopped machining the block for one since they went electric.You can run a electric as well. Never heard of a adapter from FI to a 2barrel.
Vortex? huh? The 87-94 350 engines that had TBI have the 4 center intake bolts at an angle, but it's less of an angle than the earlier engines. The 95-up "Vortec" engines have all intake bolts vertical, and there aren't as many of them as the earlier engines. You can get any pre-87 intake and waller out the 4 center bolt holes until they clear. Or get an intake designed to fit your heads. Or, better yet, find an earlier engine, so you don't have to deal with that crap. also check to see if there's a hole for a fuel pump pushrod, unless you're running an electric pump.
As mentioned you can use a earlier intake with some work, proper intake for your heads, or change heads. Your block might have a factory roller cam in it, which is a plus. You’ll know when you pull the intake. There will be a “spider” holding plates to retain the lifters. If the cam is roller and factory, it won’t be a performance cam. Only real issue with your heads is the center bolt valve covers don’t lend themselves to the “old school” look. also, if you have the factory roller cam, when you get a different distributor, you’ll need the proper gear for it to use it with the roller cam.
If it still has the TBI heads (Which are the worst flowing production GM heads ever) you will need a TBI intake manifold. I'd switch to Vortec heads (96 and up) then buy an intake that fits Vortec heads. They don't have center intake bolts, just 2 at each corner.
Some of those EFI engines did not have a lobe on the cam for a mechanical fuel pump......you will need an electric pump if yours is one of those.
I removed the fuel injection from a '95 350 (I am in Canada and the '95 350 was not a vortec engine), and installed a factory aluminum 1987 Monte SS intake (305 engine in the Monte ... '87 was the first year for centerbolt valve covers here in Canada) on the 95 350 heads. This intake takes a Quadrajet carb so that is what I ran. With the fuel injection off the engine, I was able to determine that this was a non-roller engine but it was roller capable so I hit the wreckers and snagged all the roller stuff from a 92-93 (I forget which year) Buick Roadmaster. Installed everything and I had a Quadrajet carbed, roller cammed 1995 350 in my daily driver G-body. This block was not set up for a mechanical fuel pump so I used a Carter electric (which I hated, sounded like a helicopter in the trunk).
Many of the late aftermarket intakes now come with oval shaped holes for the intake bolts, and they come with inserts that fit the holes for either old style, or new style head angles. So the same intake can be used on any generation head. I have a 1990 BC roller motor I built for my '39 Chev coupe, and I bought it as a short block. So rather than mess with center bolt heads I bought early 70's LT1 heads and had them rebuilt, and use on my later engine. It solved all the issues of later valve covers, intakes, etc. for me. My 1990 motor was machined for fuel pump so I simply put the pushrod and plate on it, and installed a mechanical pump. I think this is the best of both worlds. A late model roller block, and early heads, and intake. I love this engine.
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