Fuel Pump Part # Help

[Jeff C.]

My 1962 had a #4657 fuel pump (s/b a #4656). When I tried to remove it in preperation for pulling the engine there was not enough clearance between the frame and the engine to get the pump out. Maybe if I had work it longer I might have been able to but since I was pulling the engine I left it on. Is this pump larger in diameter than the 4656? A pump that I had from 1965 Impala was signicantly smaller but all one piece. Anyone (Joe Lucia) know what the application for the 4657 pump was. Thanks for any help!
Jeff Cheney 29688

[Joe L.]

Re: Fuel Pump Part # Help

Jeff-----

The AC 4657, aka GM #5621665, fuel pump was used for the following:

L1958-61 passenger car with 348
1959 passenger car with 283 cid and FI
1962-66 passenger, Chevelle with 327
1962 passenger with 409
1963-65 Corvette with 250, 300 hp

It was also SERVICE for 1959-62 Corvettes, but I'm not sure that it was the same pump used in PRODUCTION. It may have been, though.

[Jeff S.]

Re: Fuel Pump Part # Help

Jeff

My late'66 (July) car w/base 327 engine has 4657. '66 Judging manual indicates that 4657 is correct for '66 model year 327/300 after Mar 28 '66.

[Mike E.]

Re: Fuel Pump Part # Help

Jeff--
4657 and 4656 are indentical except for potential differences in the orientation of the inlet and outlet. (and all that is simply moving the center body of the pump either clockwise or counterclockwise in relationship to the top in order to get the fitting outlets in the proper spots for different usages.) Likely the reason that you had issues with removing the pump is that the cam lobe had the fuel pump push rod completely extended, and that limited the travel of the body of the pump. I've changed a number of them with the engine in the car, and it's not a picnic, but it's very doable.

[Jeff C.]

Re: Fuel Pump Part # Help

Thans everyone
Jeff