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Old 08-22-2025, 02:20 PM   #1
ron350
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1975 HEI Distributor Weight Plastic Button?

I am atermpting to restore my 75 HEI #1112880 and can't find the plastic buttons (pads) that the centrifugal weights sit on.

I have found several discontinued part numbers for the weight bushings but nothing about these plastic buttons.

Thanks Ron.
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Stock 75 C10 step side.
350 2 BBL, 350 trans. 150K miles.
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Old 08-23-2025, 07:11 AM   #2
Dead Parrot
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Re: 1975 HEI Distributor Weight Plastic Button?

IIRC - 75 was the first year for HEI. Possible those were a one year only thing and left off later models, thus hard to find. 1975 also called for a special wide gap plug with a .060 gap vs the .045 on all most post 75 HEI engines. From experience, the later .045 plug works just fine. I think GM was still figuring out the HEI thing in 1975.
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Old 08-23-2025, 10:47 AM   #3
ron350
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Re: 1975 HEI Distributor Weight Plastic Button?

Hello Dead Parrot.

It would apear GM used those centrifugal weight buttons for several years in all GM hEI distributors. The buttons in the picture are out of a late 70's Oldsmobile HEI.
I was just wondering if GM ever sold those buttons separate from the shaft?

From what I have read it was the centrifugal weight nylon bushings that were only used in chevy HEI's from 1975 to 1979. After lots of searching i have found someone in Australia who claims to have some of these nylon bushings but will not ship to USA.

https://www.ebay.com.au/itm/23392641...physical_ms%7D

These 75-79 bushings are not the same as the bushings in recurve kits because Chevy used a special small weight pin during those years.

Here is a list of obsolete part numbers i have found for those bushings. Don't shoot me if any of these part numbers are wrong.

Delco D337A

GP Sorensen 72373

Echlin DP112

Echlin DP109

Borg Warner DG13

It would be great to if those weight bushings were still available.


Just to clear things up a little the holes in my 1975 HEI centrifugal weights are 0.210".
The diameter of the pins the weights hang on is 0.154".

So you can see this setup needs a special thin bushing.

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Stock 75 C10 step side.
350 2 BBL, 350 trans. 150K miles.

Last edited by ron350; 08-23-2025 at 11:28 AM.
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