Boo -

Carter YF 4085s, 4369s, and 4371s were all original equipment on 250 CID Chevrolet with standard transmission. Carter YF 4085s, 4370s, and 4372s were all original equipment on 250 CID Chevrolet with automatic transmission.

Of possible note to several of you: 4371s was also original equipment on 292 CID Chevrolet. grin

While the YF for the Foorrdd would probably work, a YF specifically calibrated for Chevrolet would probably work better. We have stated for years that the most expensive carburetor one will ever buy; is one given for free by a friend or neighbor which is incorrect for your application! :p

Also consider that all the the YF's in this post as well as the Foorrdd YF originally mentioned by Boo are smog emission carburetors, so may (or may not) be lean on idle (early smog carbs were pretty much only effected at idle).

Jon.

Good carburetion is fuelish hot air
The most expensive carburetor is the wrong one you attempt to modify.
If you truly believe "one size fits all," try walking a mile in your spouse's shoes!
The Carburetor Shop