The Stovebolt Site Forums The Shop Area The HiPo Shop 270 GMC carb swap ?

Hi All,

Last winter I bought a '51 GMC panel in Portland. It had previously been converted to a 270, with 12 volt. This 270 was running but rattling worse than my F%#d diesel pickup. A spare 270 was included in the deal (from Old Car Parts in Portland). We're engine swapping right now. The original 270 had a rebuilt single barrel carb and vintage headers (which we're using).
Is there such a thing as a 2 barrel carb that will bolt up to an original intake manifold, or is the only option going to a multi carb manifold ?

Thanks

There is an option- the GMC 302 intake manifold is set up for a two barrel carb and bolts right up to your 270. There are two bolt patterns. One has three bolts to fit the Holley AA-1 (Stromberg 97 style). The other has four bolts and will fit a Rochester 2GC style. Some (maybe all?) of the 302's don't use vacuum advance, but you can drill the base of the carb and add it if your carb doesn't have it.

The Military 302 manifolds are available NOS from places like Memphis equipment. They do have ports drilled in the manifold for vacuum. they are the 3 bolt carb style.

I ran a otherwise stock 270 with a 390 cfm 4bbl. It woke that 270 up quite a bit. It would have really screamed with a cam and headers. The 4bbl intakes are available from Patrick, or Larrowe. They are highly reccomended.