Holley accelerator pump cover

[Randy R.]

[Joe L.]

Re: Holley accelerator pump cover

I have a 67 L79 May built car. The accelerator cover has philips screws. The judging guide says it should have clutch head screws. I have had the car since 68. The carb is original. No one has changed the cover since 72. I have done all the carb maintenance since then. I don’t recall it ever being changed. Should I replace the cover? I am reluctant to change what I have just to match the guide.
Wwhat you advise me to do?

Thank you,
Randy

Randy------


I don't think there would be any difference in the cover regardless of what drive type screws were used.

I do know that Holley carbs of the period usually had clutch head screws for the accelerator pump cover. I remember that all too well from my 1968 Chevelle L-78.

[Mike M.]

Re: Holley accelerator pump cover

i've never encountered anything but clutch head fasteners on the hollys. if u need for, i'll look and see if i have any, let me know. mike

[Gene M.]

Re: Holley accelerator pump cover

I think the answer was covered but you may find interesting this that Jerry posted years ago. It illustrates the different screws and covers Holley use over the years.

https://www.forums.ncrs.org/showthre...s-4-variations

[Timothy B.]

Re: Holley accelerator pump cover

It's always been my understanding the 64-65 holley used the clutch head screws with a pump cover that is countersunk for the screws.

I would keep the Phillips screws because I believe for the Holley 3810 in 1967 they are correct.

The clutch head screws are the same screws that hold the secondary metering plate to the main body o the 4160 Holley.

[Joe R.]

Re: Holley accelerator pump cover

This is a picture of an early Holley Pump Cover and screws. Changing the screws to clutch heads means changing the cover plate also as they are countersunk.
Jerry's pictures illustrate this very well also.

JR

[Michael M.]

Re: Holley accelerator pump cover

Randy:

I looked at a lot of original '67 List 3810's when I was shopping for one. All of the accelerator pump covers I saw had phillips head screws with lock washers like the one in the pic below (dated 751 - first week of May 1967).

[Gary S.]

Re: Holley accelerator pump cover

I have phillips screws on the accelerator pump on these orig carbs on my cars:

66 3370 Vin#22300 dated 634
67 3810 Vin#1866 dated 673
67 3810 Vin#19567 dated 743

[Gene M.]

Re: Holley accelerator pump cover

OK, from the discussion so far there seems to be configurations that use clutch flat head screws w/ counter sunk hole and others that have Phillips head screws (of differing lengths) w/casting configuration differences on 66-67 3810 Holleys.

It would be interesting to access the absolutely original unrestored ones for accelerator pump configuration and screw usage. Is it possibly Holley used differing configurations?

My 67’s Holleys I personally restored them myself. When I get back in garage, I’ll check the accelerator pump casting configurations. I don’t recall if I replaced the original screws or used new ones. The casting style should indicate the type screw used. If they have a c-sunk hole that should tell the clutch head was used. Any flat hole a Phillips head.

[Joe L.]

Re: Holley accelerator pump cover

I have a 67 L79 May built car. The accelerator cover has philips screws. The judging guide says it should have clutch head screws. I have had the car since 68. The carb is original. No one has changed the cover since 72. I have done all the carb maintenance since then. I don’t recall it ever being changed. Should I replace the cover? I am reluctant to change what I have just to match the guide.
Wwhat you advise me to do?

Thank you,
Randy

Randy-----

I thought you were talking about countersunk type screws but with a phillips drive. I think I may have seen those on later Holley "restoration" carburetors. I'll have to check when I get home from this trip. I do not ever recall seeing the pan head type phillips screws but, obviously, they exist as pictured here.

[Randy R.]

Re: Holley accelerator pump cover

Thank you for the info.

Randy

[Randy R.]

Re: Holley accelerator pump cover

I found a picture of the botttom of a base engine carb w/ k19 on page 412 of Noland Adams guide vol 2. This is also used on a L 79. The picture shows a pump cover with philips screws.

Randy

[Joe L.]

Re: Holley accelerator pump cover

All-----


Well, this is interesting. There were two different screw types used for the accelerator pump covers and several different configuration covers. The GM information I have is a bit confusing but this is how I interpret it.

1964-65 with SHP, 1966 with SHP, 1967-69 with 3X2, 67-69 with L-88, and 1970 LT-1 used cover GM #3867991 aka Holley 34R-2752A. I believe this is the cover with the countersinks for the screws. I do not understand why the cover in JR's photo shows 34R-2178. I have seen covers bearing that number with no countersinks and designed for the pan head phillips screws. The 3867991 was discontinued from SERVICE in September, 1972 and replaced by GM #6263029. The latter has no countersinks and is designed for the pan head phillips screws.

1967 Corvettes and all 1971-72 with Holley carb used cover GM #2386309, aka Holley 34R-2183A. This cover is designed for use with pan head phillips screws. However, I have seen two different designs of this cover. One version has reliefs in the corners for the screw heads. The other version has a round, raised center section with the entire perimeter relieved for the screw heads. This cover was discontinued in June, 1974 and also replaced by the GM #6263029. The latter cover is completely "flat" with no reliefs for the screw heads.

I do not know what cover was used by non-SHP 64-66.

[Ron G.]

Re: Holley accelerator pump cover

In support of what Gene Manno said, I know that the Holley's that came on LT-1'S & LS-6 cars used 2 different types of hardware that I have seen for attaching the carb to the intake manifold. I have seen standard nuts and nuts with a flared shoulder on them with the latter being more popular. I know this is not relevant to the fuel pump cover, but it does show that in some Holley applications it was not uncommon to see a different configuration piece of hardware.

[Michael F.]

Re: Holley accelerator pump cover

all of my 67s I have owned have had phillips head. all documented cars.