Large Cap vs. Small Cap Dizzy Gear Sizes
10-31-2008, 09:45 PM
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Car: 1991 Z28
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Large Cap vs. Small Cap Dizzy Gear Sizes
I am running a large cap dizzy with a hyd. roller cam and would like to change the dizzy gear to the factory 1991 melonized gear.
Are the large cap and small cap SBC distributor gear sizes the exact same?
Are the large cap and small cap SBC distributor gear sizes the exact same?
10-31-2008, 10:20 PM
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Car: 1991 Z28
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Re: Large Cap vs. Small Cap Dizzy Gear Sizes
Thanks. What would be the difference between the .500 and .491 sizes I am seeing?
10-31-2008, 10:24 PM
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Re: Large Cap vs. Small Cap Dizzy Gear Sizes
Aftermarket distributors use a heavier .500" shaft.
11-01-2008, 01:07 AM
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Re: Large Cap vs. Small Cap Dizzy Gear Sizes
The small cap distributors need a tiny 0.427" shaft gear
Last edited by AlkyIROC; 11-01-2008 at 01:14 AM.
11-01-2008, 03:01 PM
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Car: 1991 Z28
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Re: Large Cap vs. Small Cap Dizzy Gear Sizes
So I'm assuming a stock GM melonized dizzy gear from say the 1991 model year probably won't fit an eBay special large cap dizzy?
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11-01-2008, 04:02 PM
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Re: Large Cap vs. Small Cap Dizzy Gear Sizes
91 is when they started using the small cap with the externally mounted coil. The small GM small cap is a computer controlled distributor with no weights or springs inside it.
A small shaft sized gear for a small cap won't fit on a large cap or aftermarket distributor. I suppose if you had a lathe or milling machine to accurately enlarge the hole, it would work. Cheaper to just buy the proper gear.
A small shaft sized gear for a small cap won't fit on a large cap or aftermarket distributor. I suppose if you had a lathe or milling machine to accurately enlarge the hole, it would work. Cheaper to just buy the proper gear.
11-01-2008, 08:34 PM
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Re: Large Cap vs. Small Cap Dizzy Gear Sizes
The Corvette only used the big dist. The new gm gears are support to melonized. I got a bronze one for my small dist. Crane makes them.
11-01-2008, 11:07 PM
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Car: 1991 Z28
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Re: Large Cap vs. Small Cap Dizzy Gear Sizes
hmmm....thanks for the information Setphen.
So is there a GM melonized gear that would fit onto the large cap dizzy I have? I've found some on Summit's site but don't know my exact size....I still see the .500 and .491 sizes which I do not know the difference between.
I cannot justify 50+ bucks for a dizzy gear when the GM melonized one (that probably won't fit) is less than $30.
So is there a GM melonized gear that would fit onto the large cap dizzy I have? I've found some on Summit's site but don't know my exact size....I still see the .500 and .491 sizes which I do not know the difference between.
I cannot justify 50+ bucks for a dizzy gear when the GM melonized one (that probably won't fit) is less than $30.
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