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Discussion Starter #1
The Holley on my '68 cal special was in really bad shape and needed imedieate repair. The carb shop wanted $135 to rebuild it so I decided to try and fix another Holley I had lying around. It's problem was it was leaking and a PO used silicone on the gasket between main gasket and base plate. I cleaned it all off and found it was missing two of the 8 screws. I went to the local hardware store o pick up a couple of these screws........wrong! Before going to the store I was going to steal them off the bad Holley but that carb is the two piece kind and is totally different. Well I looked and looked for about 20 minutes before asking the clerk if he knew anything.
Seems this screw is somewhere in the middle between a 10-20 and a 1/4-20. nobody knew anything about it and have never saw anything like it. Well I had to get the 1/4-20 and tap the 2 holes to this size. Carb no longer leeks and really gives my car a hell of a lot more power than the 4100 I had on there that I borrowed from my '67.
Anyone know anything about these screws?
 

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I don't want to burst your bubble, but most of the holleys I've had only had 6 screws....I've never percieved a need to use all 8 holes...as a matter of fact, on some intakes those extra 2 will be exposed to the intake plenum.....can you say pray they never loosen up!!!!!!

Many of us have played with holleys....next time ask buddy!!!! /forums/images/icons/smile.gif
 

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Discussion Starter #3
What is this "bubble" you are talking about?
Putting in the 2 missing screws did fix the leak, I am using 4 hole heat insulator so falling screws are not a problem.
If your screws are backing out you are not torquing them properly, I have NEVER had a loose screw.
I don't want to burst your "bubble" but Holly did not machine in those holes for nothing. Yes there may be instances where they might not be used but if they served no purpose at all Holly would not go through the expense of machining them in.
As for my question you did not answer...
Do you know what size they are?........... I didn't think so.....
 

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there is such a thing as a 12/24. Maybe that's the size it was. As you've discovered, it's not very common.
 

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Discussion Starter #5
Might be a 12, it was defenately a 20 tpi. The 1/4 -20 tap went in very eaisly. is there a 12-20?
 

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#12 24TPI machine screw size. Major thread OD of .2105". Clearance drill #2 or .221". Tap drill #17 or .173".

If you need further info on Holley parts, I have a small warehouse in the race car trailer box.

I fill all the bolt holes too...keeps the throttle plate nice and flat...*G*

Have fun!
 

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Discussion Starter #7
Thanks Pat,
That explains it, I could not believe the hardware store I went to didn't have it. They have a huge assortment of that stuff.
 

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Geez, try to help....

Guess always being taken wrong is the price I pay for being VMF's resident jerk!!!
 

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Discussion Starter #9
I don't think you are a jerk, but people like me take offence when you put them down by implying that we live in a bubble.
Call it just human nature but people just don't like to be talked down to, expecially when the person doing so is less than 100% informed on the topic.
No hard feelings, just take it easy on people.
 
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