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RJ 01-25-2009 05:29 AM

GM Stocker rear end choice
 
Which GM rear end would be quickest yet be durable enough for an automatic stocker weighing 3900 lbs. and running 10.80's? - gears would need to be available in the 5.13 - 5.57 range.

Thanks

Dragsinger 01-25-2009 07:55 AM

Re: GM Stocker rear end choice
 
R J,

what power - performance range are you expecting?

Alan Roehrich 01-25-2009 09:25 AM

Re: GM Stocker rear end choice
 
RJ, there are some guys running the 8.5 late model 10 bolt in real fast cars. I'm not completely convinced that the reduced weight and drag is enough to offset the increased risk of breakage and the increased maintenance costs. It's the same basic design as the 12 bolt, it is just slightly smaller and lighter. I'd say you could get by with doing it. I'm not sure it'll make enough difference in ET and MPH to cover the at least 50% reduction in ring and pinion life, especially when you go to 5 series gears, as the pinion gear gets really small, and that's where the weak point is.

Rich Biebel 01-25-2009 11:01 AM

Re: GM Stocker rear end choice
 
With a weight of 3900lbs and a predicted ET range of 10.80's, I have to assume this is a bigger cube engine. It takes a lot of power to run 10.80's at that weight. I would not race that with anything smaller than a 12 bolt if it was a GM vehicle. Breaking rear ends is not fun.....

RJ 01-25-2009 11:10 AM

Re: GM Stocker rear end choice
 
Yes, in asking around I'm getting the same answer, 12 bolt it is, thanks all.

Greg Reimer 7376 01-25-2009 11:30 AM

Re: GM Stocker rear end choice
 
Just for curiosity's sake,what are you thinking of building that weighs 3900 pounds and goes 10.80's? A 427 Caprice or something? Yes, a 12 bolt is the right choice.

Robert Swartz 01-25-2009 12:03 PM

Re: GM Stocker rear end choice
 
Quote:

Originally Posted by RJ (Post 102484)
Which GM rear end would be quickest yet be durable enough for an automatic stocker weighing 3900 lbs. and running 10.80's? - gears would need to be available in the 5.13 - 5.57 range.

Thanks


With this heavy a car, 12 bolt, no question.

I'm preparing to build a 34-3500 pound crate motor car and we're going to utilise a 10 bolt. I still have my concerns but after a few consultations. I am less afraid of these rear ends on a lower HP footbrake stock class car.

If I were building a high torque engine, that would be launched by either a stick or a trans brake, if I were limited to or desired a GM rear, a 12 bolt would be the only choice.

danny waters sr 01-27-2009 11:04 PM

Re: GM Stocker rear end choice
 
R J , You got mail !!

Jim Kaekel 01-28-2009 11:47 AM

Re: GM Stocker rear end choice
 
RJ: Definitely go with the 12-bolt, and with a "pro" 9310 steel gear. You will definitely break the teeth off of the gears with that much power and weight if you use a "street" 8620 steel gear. I have an Olds that I've run for quite some time, weighs around 3800 lbs. and has run a best of 10.85. Add to the fact that nobody offers a "pro" type gear for the GM 10-bolt that I am aware of.


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