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Discussion Starter #1
I am building an '80 Malibu with a mild BBC/ TH400 for the 1/8th.
Is the 7.5 worth putting mini spool and axles in? Also, what's a good gear ratio to start with? All steel car, gutted interior/ac, fender wells.
 

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LSx The World
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I dont think it would last past the 60' behind a big block
 

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itll break. i will bet the mini spool will break first then the axle. go ahead and find you a 12 bolt. it bolts right up with the conversion control arms.
 

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Had a mini spool in my 7.5 just turning in yard made all kinds of chunks in the housing. And that was be hind a 350 v8. I did run an 11.70 quarter with the 7.5 with auburn pro posi slick on spray. With the big block I would step it up
 

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Discussion Starter #8
Old thread, but same shit. '83 GMC pickup with stock 10 bolt. 468bb. Can it be built for track or shit can it?
 

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I think you'll be safer to put your money in a bigger diff. Those 26 spline axles are pretty small. Theirs a few F-body's with the GM 7.5 with the 28 spline that are in the 11's in the quarter though.
 

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I think you'll be safer to put your money in a bigger diff. Those 26 spline axles are pretty small. Theirs a few F-body's with the GM 7.5 with the 28 spline that are in the 11's in the quarter though.
The typical f body's that lasted ran 3.23's or 3.42 gears and ran autos.. The gears are so small that once you tried to run anymore then a 3.42 your chances of breaking them drastically went up.. I had customers that I'd probably put 4 or more sets of gears in before they'd bite the bullet and get a 12 bolt or 9".. New gear and labor was under 500 verses 2k to swap a 12 bolt or 9" and they couldn't afford the price difference all at one time, but once you add up multiple gear sets or posi units it's a wash.. Never had any of them break an axle since the gear or posi would give up first.. The 8.5" 10 bolts will hold a lot more power then the 7.5" and we built lot of them with good parts, but at some point most of them went with a 9" and ended up costing them a lot more in the long run..
 

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Correct. These are Auto tranny cars.One of them has 3.73's in it. So far so good.Converter is a 3000RPM Yank on 26" DR. The GM 7.5" can only handle so much and that's it.
 
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