VCCA Home Forums TECHNICAL - 1945 AND NEWER 1955-1957 '57 fuel pump questions

Fuel pump is for a '57 full size pass. car w/283ci motor. I need/want what would be original to the car.

1. Do I want the top of the pump stamped with part #4262 or the 4150? Or another number.

2. The 4262 uses a 5/16" fuel line do I use 5/16"? If not what size?

3. In regards to the center part of the pump, should the inlet and outlet be 180 degrees apart(like the 4346 pumps) or should they be about 30 degrees apart?

4. Did the '57 use the long screw fuel pumps(4346)?

5. Is the bottom cover attached with a single screw or does it have the double fastner bottom cover?

Thanks guys...

The fuel pump fits 1955-57 only.This is due to the location onf the fittings for the fuel lines.When installed on the car the fittings will be in the 4:00 o'clock and 8:00 o'clock positions-as viewed when standing along the right side of the engine.It mounts to the block in the 12:00 o'clock position.The pump has one screw on the bottom.It attaches the metal cover that has the pulsator diaphragm behind it.Short screws attach the upper and lower halves of the pump together.The pump will have AC on the bottom and also have AC on the top between two of the screw holes.The flange of the pump will be stamped either 4150 or 4262.

The 4346 pump is for dual 4 barrel cars.It has a greater capacity to keep both carb. bowls full.Has 2 screws on the bottom.long screws holding pump together and larger holes for the fittings...but the fittings are in the same location.

The fitting threads in the 4150-4262 pump are 1/8" pipe thread and the car used 5/16" gas line.The dual 4 Bbl. cars had 1/4" pipe thread for the fitting and used the larger 3/8" gas line.

In the following years the inlet and outlet fittings were in different positions but the pump was basically the same.

Thanks a lot, Chevgene.

I assume you meant '55-'57 not '55-'55 in the first line. Right?

Sorry, I just corrected the post.That was a mis-type or mistake or whatever.First one I made today.

chevgene: i trying to get the 3 pieces of a pump together for gator's 57 chevy. agree with all you stated in the above post but after rooting thru about 50 of my small block fuel pumps, i have none that have AC logo on the bottom cover. as a matter of fact, they're all stamped steel, single fastner covers. got a bunch of pot metal 2 fastner bottom covers with AC logo but i think the pump gator needs takes a single fastner cover and although i only have stamped steel bottoms without logos , not sure what bottom cover he needs.thanks, mike

Gene? P.S. mailed you a snail mail letter today.

There are three parts to the fuel pump.
the top pot metal cast housing.The lower pot metal housing.The bottom stamped steel cover.
There are no markings (AC) on the stamped cover.Each of the pot metal housings will have the AC letters cast into them - if its a genuine AC pump.The correct bottom stamped cover will have one hole in the center -aligns with the hole in the lower housing.

The 1955-57 fuel pump did not have a long life expectancy.Usually about 40,000 miles.There were many brands of replacement pumps made and they had no AC markings.

Also in 1957 and up all Corvettes used the 4346 pump - including the single 4 barrel jobs.If you have worked on a lot of Corvettes thru the years you may have acculminated many of these to add to the confusion.

If I missed something let me know - hope this helps,Gene

gene: your input appreciated. glad to hear the bottom cover is stamped steel with one fastner(as that's the only variety in my parts collection of single fastner bottoms). will get gator's pump out to him. thanks, mike

Thanks guys, you are great, which is why the VCCA is great.

Thanks again...