I've read posts that stated all GM 6 Cyl. fuel pumps are interchangeable. But on E bay they aren't. Is this just cosmetic? I know the GM 6 Cyls. total changed in 1963, but I'm talking about from late 50's to early 60's.
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
Chris, Can you clarify which GM 6 cylinders you are asking about? Definite differences between Chevy and GMC (inline) 6 cylinders fuel pumps. There are also some variations for the Chevy, depending on the years and the model/series involved.
If you can give a more specifics on engine size/year, we should be able to help you find the info you seek. Generically speaking, there are two primary fuel pumps for those years. Up to/including 1957 AC 4149 is called for in many of the Chevy Master Parts Books and for 1958-62 AC 4434 was the primary fuel pump. There are a few variations for some specific bigger truck models equipped with air brakes, but these two are the primary models.
One other important note, there are a ton of "off-shore" made wanna-be fuel pumps which have caused a bunch of grief for many Bolters as they are literally inoperative junk out of the box. More info available when you let us know more details on your questions.
~ Dan 1951 Chevy 3 window 3100 Follow this story in the DITY Gallery "My Grandpa Carl's Truck and How it Became Mine" 1966 Chevelle (Wife's Hot Rod) | 2013 Chevy Silverado (Current daily driver) US Army MSG Retired (1977-1998) | Com Fac Maint Lead Tech Retired (1998-2021)
Chris, what fuel pump are you using right now? If it's an original pump or a pump built or re-manned 25 or 30 years ago, then your best bet in my opinion is to rebuild it or have it rebuilt.
New pumps are complete garbage and not working out of the box is no exaggeration.
You can buy a rebuild kit or send your pump to one of several companies to have it done. I have used Then and Now Automotive several times for different vehicles and am extremely satisfied.
Last edited by Gdads51; 02/18/20262:43 AM. Reason: correct to new web address
1950 Chevrolet 3100 (Ol' Roy)
1939 Packard Standard Eight Coupe (The Phantom) | 1956 Cadillac Coupe de Ville (The Bismarck) | 1964 Ford Galaxie 500 coupe |1966 Ford Mustang (Little Red) | 1969 Pontiac GTO (The Dishpit) I 1979 Ford F-100 | 1976 Ford F-150 (Big Red) | 1995 Ford F-150 (Newt)
I'll say this... My 1940 216, 1953 216, two 1957 235s, a 1959 235 and 1957 261 all use the same application fuel pump. Whether it is a glass bowl AC, an AC without glass, a Carter or a much later non-rebuildable AC with the crimped housing, they will fit any Chevy 6 cyl Stovebolt, which is the model we are discussing here. All have pressures suitable for the infamous Rochester B. All have been used here on the farm at some point in the last 70 years with equal success. All but the crimped AC are rebuildable. The Carter is more complicated than the AC to restore.
~~ Jethro 1954 3100 Back to Life In the Dity Gallery 1951 3100 (gone) / 1956 4400 (still in the neighborhood) / 1957 6400 with dump body (retired) / 1959 3100 panel (in the woods junked) / 1978 Custom Deluxe K10 / 1993 S-10 4.3 / 2004 Chevy Crew Cab / 1945 John Deere H / 1952 John Deere B / 1966 John Deere 2510 / 1967 John Deere 1020
Mike, Is your post a statement of fact, or a question regarding valve size? There is difference between clocking between fuel pumps for cars vs trucks. The truck pump inlet and outlet is parallel to the crankshaft, while the car pump inlet and outlet is a number of degrees off from parallel to the crankshaft to avoid fuel line interference with the side motor mount of the car engine. It is easy enough to bend the truck supply line so that a car fuel pump will work. I am curious if the check valves were increased in size over the years to account for increasing displacement.
1952 5-window - return to "as built" condition | 1950 3100 with a 235 and a T-5 transmission
A statement that all the pumps will physically bolt on. But there are differences in the clocking, and depending on the year and application, differences in the check valves.
All my pumps are in a box that is currently not accessible (had to store half the basement on one side to put a Christmas train platform up for one of mygarnd boys, lol), otherwise I would have posted a couple of photos showing some of the clicking differences and valve size differences.
This is one instance where a DIY rebuild probably isn't the best choice. Bite the bullet and get a pro outfit like Then and Now do the rebuild- - - -"Buy once- - -Cry once!" Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
Last edited by Gdads51; 02/18/20262:44 AM. Reason: correct to new web address
1950 Chevrolet 3100 (Ol' Roy)
1939 Packard Standard Eight Coupe (The Phantom) | 1956 Cadillac Coupe de Ville (The Bismarck) | 1964 Ford Galaxie 500 coupe |1966 Ford Mustang (Little Red) | 1969 Pontiac GTO (The Dishpit) I 1979 Ford F-100 | 1976 Ford F-150 (Big Red) | 1995 Ford F-150 (Newt)
