08-06-2008, 02:56 PM
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CC Member
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Join Date: Feb 2006
Location: Scottsdale,
AZ
Cobra Make, Engine: Superformance, Roush 427R-095, Pro Systems carb, 2" headers, Buckshot Racefab side pipes, 10s off idle start
Posts: 705
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Not Ranked
I'd get the .82 5th if I had to have the new 3.46 Superformance rear end gearing. I'd want a 3.73 rear gear more than I'd care about which 5th gear though.
My car was with the older 3.73 rear gear. The 28 inch tall 275/60 15 tires worked great with the .64 5th gear at 1600 rpm or higher if going up hill, about 1800 rpm flat or about 2000 rpm if going down hill. The more decline the more the car would get ahead and try to unload the drive line if at lower RPM. The motor had quite a bit of low rpm torque which probably helps. Under acceleration the 4th gear with 28 inch tall tires was good for about 140 mph, so the option of .82 or .64 5th was sort of a prefference wether you wanted to fart along with a cruiser 5th or have a more sporty feel with the 4 to 5 shift. I can't imagine continuing to accelerate after 4th though.
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