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What is the port size of the 216? I’m looking at an offenhouser manifold on eBay and it shows the following specs. I just don’t know if I need the port adaptors or not.


Offy #1034 lightweight cast aluminum manifold

Fits 216-235-261 Chevy 6-cylinder

1936-52 engines w/ Manual Transmission

Carburetor Port Diameter: 1-1/2"

Intake Port Diameter: 1.40"

Carb Bolt Center-to-Center: 2-5/8"

Truck is a 1940 Chevy 1.5 ton 216.

"Fits 216-235-261 Chevy 6-cylinder

1936-52 engines w/ Manual Transmission"

These specs do not "match".

There were no 261 engines until 1954.

The Offenhauser 1034 is the original intake port size for all 216 (including yours) and early 235.
The Offenhauser 1035 is the larger size for later 235 and all 261.
The 2-5/8" dimension is incorrect, it's 2-11/16" (S.A.E. #2 flange).

Thank you, panic

A more appropriate question might be where to find a carburetor small enough to work in a dual application on a 216. Since the port spacing is the same on all those engines, making the manifold fit isn't much of a challenge. Making a too-lean engine perform is another matter entirely. I can't think of many less-desirable situations than an over-carbureted 216! Back in the early 1960's, a high school friend put a 3-carb manifold on his 51 Chevy coupe, and then adapted Stromberg 97 2-barrels to it. In less than a week, he was back to running a single carb. The thing never got out of his driveway, which had a slight upgrade. It caught fire twice from backfiring, trying to make it to the street. Maybe a couple of carbs for a CJ-2 Jeep 4 cylinder?
Jerry

Jerry, atta' boy. Doc. It is not my intention to offend ANYONE! I have an original carburetor that Ken Miles modified for me for my 58' MGA. It would be my first choice with a really weird adapter plate. The only reason I hold on to it is because he had a super modified MG-TF. When I sold the MG I put the carb. In a fancy globe with a walnut base. Maybe It would work? I have no idea what the CFM would be but, justhosenround would probably know. I think he was producing around 90 h.p. which is a lot from a 4cyl. sewing machine. Loved the heck out of driving it. AAH, those were the days that we could do stupid things on cars and not have anyone say anything about it. Doc.

Carter YF carbs if you want to run dual singles. The W-1 may also be an alternative but I have never run those carbs only the YF, YH side draft and Rochesters (which I would not recommend). Another alternative, use the small carter/Weber carbs that tom Langdon sells over at stovebolt engine company. These would be preferable in my view. You will have to use adapters because those carbs are two bbl progressive carbs, but they are smaller then the Holly/Weber 5200 pinto carbs. Nice small primaries, larger secondaries. They run really well as pairs right out of the box Without much fussing around. If it was a 235, you could used the carter/Weber or the Holley/Weber, I would go with 1974 ford pinto holly/Webers, the fuel inlet is threaded.

Two Carter WO carbs for the 134 cubic inch Jeep 4 cylinder will only slightly over-carburete a 216- - - - -they can handle 268 cubic inches. That's far more capacity than a 216 can use, but at least it won't have as many flat spots, backfires, and twitchy throttle response quirks as one with a pair of carbs that can feed 432 cubic inches, or 470 cubes, right?
Jerry