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I have a quadrajet with the application number removed and I am trying to identify it by the casting numbers. I’m referring to the numbers cast into the pieces in a circular pattern. My carb has 7035221 cast into the main body, 7037600 cast into the baseplate and 7938161 cast on the inside of the air horn. Does anybody have any quadrajet with the same numbers and if so what is the application number for that carb? I was told the baseplate was a Chevy piece made by Carter. I have seen similar baseplates on mostly 68 carbs both Olds and Chevy, mostly carter some Rochester, but I couldn’t read the cast numbers. My baseplate also has an unusual idle bypass system with the holes coming through the primary throttle bore that I am curious if Oldsmobile ever used. I have found one 7028251 carb with the same body number. It it did appear to have the same style baseplate without the idle bypass. Casting number off of any 66-74 Oldsmobile quadrajet would be great.
Last edited by 4speed455; Nov 1, 2020 at 02:34 PM.
Unfortunately, those same castings were used on multiple applications, so the casting numbers alone won't give you the exact application number. To complicate this further, Rochester typically didn't list the casting numbers in the service parts pages, they listed the assembly numbers. For example, the 7038186 throttle body casting would actually be listed under a different assembly part number that included the throttle shafts and plates.
Thanks for the info Joe, I know the casting numbers won’t tell me the exact application, I guess I am more curious to see if the casting numbers are used by Oldsmobile and if so what years. I am more curious about the baseplate since I was told it was a Chevy piece but I have seen similar ones on Olds carbs.
So after further research I think I have positively ID the original application of this carb. It looks to be a 7028251 that has been converted to integral electric choke and has possibly a Carter baseplate for Chevy. I am still curious if anybody has anything that matches these cast numbers, specifically the baseplate on an Olds carb.
