Help ID ing C2 396 fuel pump. What to purcahse?

[mike 32580]

I just removed the fuel pump from my 65 396. It is an AC with a stamped number of 4D5D42080.
I want to replace it but I need help to decide what is correct. From what I can tell from various supplies info, this one is not.
It has a bent inlet of 90 degrees and a threaded output to carb.
It is a direct bolt on to the block.
The car is a June build. I would appreciate if one of you experts could tell me what I should purchase. Also, out of curiosity, what was the application for this pump?
Thank you.
Mike

[Joe L.]

Re: Help ID ing C2 396 fuel pump. What to purcahse

Mike-----

The pump that you have is not correct for your application. This particular fuel pump is a GM #6442080 also known as an AC type 40987. Type 40987 is a very widely used fuel pump for 1969 to 1988 Chevrolet passenger cars and trucks (but NOT Corvettes) as well as many 1977-80 Buicks, Oldmobiles and Pontiacs. The curious thing is that for Chevrolet this is a SMALL BLOCK fuel pump. What I expect has happened here is that what you have is a "rebuilt" fuel pump. In commercial rebuilders operations, units are stripped down to basic components and then these components are used to "build" a rebuilt fuel pump. Since the upper casting component of small block and big block Unitac type AC fuel pumps is the same, a small block casting could be used to "build up" a big block fuel pump. Among other parts, the pump arm would need to be changed since the small block and big block arms are different. Of course, the casting would retain whatever numbers were originally stamped on it.

I do not recommend the use of rebuilt Unitac type fuel pumps. These pumps were never designed to be rebuilt and I would be uncomfortable with using such a pump, regardless of whether it was rebuilt by a commercial rebuilder. These sorts of "rebuilt" pumps are usually done for VERY LOW BUDGET automotive repair. New Unitac-style fuel pumps are so inexpensive that rebuilders would have to cut every corner possible in order to put a unit on the market with a cost advantage over new.

The original AC fuel pumps for your L-78 application are GM-discontinued. "Reproductions" are available from many of the Corvette parts vendors. However, I think that many of these are actually rebuilt type pumps. Once again, I would not use one of those for "originality" or any other reason. If it is a guaranteed NEW pump, that would be fine.

Aside from the issue of originality, I do not see why the 67-69 Corvette fuel pump, AC type 40482 which is still available, would not work for your application. Some slight "adaptation" of the inlet might be necessary, but I would think that the pump would work fine.

All big block fuel pumps are direct mount; they do not use a seperate mounting plate like small blocks.

[mike 32580]

Thanks Joe !

Joe,
Thank you. Your knowledge solves the mystery.
I will take your advice and order the new 40482 pump.
Mike