I'm taking off the carb I threw on my 65 442 just to get it running. It gets good readings under load, but way lean at idle. I picked up a Carter AFB (?) 3721S from a neighbor who was going for more gas. Thought it wasn't enough for his old 283.
Anyway, it's almost new and I paid $50 for it so what the heck. It's showing as stock for a 64-65 Chevrolet 300 horse 327 standard shift. It has slightly larger secondaries than a square bore, but not as big as a spread bore. I'm wondering if it will fit the stock intake manifold on my f-block 455. The gaskets that came with it are one of thin material, and one 3/8 inch thick plastic. Looks like he was using both. I'm trying to figure out where the groove on the plastic gasket goes. It can go toward the front, toward the rear, and there's a wider side to the groove. Should the wider groove section be top or bottom?
These are the things that make a man age.....
Any thoughts would be appreciated.

 

Think I've got some figured out. On the 300 horse 327, the paper gasket goes on the intake and the 3/8 plastic insulator goes between the paper gasket and the carb base. Not sure if the 455 Olds engine requires the insulator or not, but I'll keep digging.
Some talk of the Corvettes using another steel gasket as well, but that's something to do with exhaust heat protection on the Chevy intake.

 

I don't think that will work without a square to spread bore adapter on a 455.

 

I have an adapter plate if I need it. Probably won't be able to work on this until the new year. Never knew I'd be so busy in retirement. Just trying so sort this out mentally, so when I play with it again I have a better understanding of it.
I've swapped lots of carbs over the years, but usually I have the intake and carb together, and see what gaskets are used and how. This is more a mish-mash of parts. What I should be doing is finding a working stock carb for a 70 455 or similar year, with the heat pipes that go into the manifold, and get closer to stock. I found a guy who wanted $125 for an old core carb and pipes for the 455, but that just seemed like too much. I'd want it in usable condition for that price.
Maybe I'm just cheap !!

 

dave, i have no idea so i havnt chimed in, but i feel your confusion, is there an imprint on the bottom of the carb to match that gasket??

 

Hi Stan,
There's an imprint on the paper gasket that shows the insulator imprint. Not clear whether the groove in the insulator was wide side down or thin side down. I think there are two ports on the bottom of the carb that need to be joined together by vacuum, so I'm guessing thin side down, wide side toward the carb base. Wish I knew what those ports were for. Maybe vacuum to operate the secondaries or something, but I'm just guessing.
My carb guy seemed to think if I could bolt this thing on, if it fit the bolt pattern, it could be made to work. He was on the phone and working on someone else's car at the time, so he may not have even understood what I was trying to tell him.
I hate not knowing everything !!

 

I'm old and memory isn't what it used to be, but, that AFB doesn't look like what came on the 327's.
Not an AFB expert, but, as I recall, the one that came on the 327's had a smaller venturi area (See pic).
I think the one in your pic was a called a "Daytona" AFB" and was used on bigger engines like 409's,
some of the big block Pontiacs, Fords and Mopars.
Hopefully, someone more knowledgeable will chime in to confirm or deny.

 

It's possible that I'm wrong. Just going by the number on the front. When I look it up on various lists, it always shows as 300 horse 327 (Corvette) 1964 1965, some lists show also 1963. Also they show as standard transmission.