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Auto Racing/rear end gearing

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Question
HI, I have a buick regal with a SBC and a TH350 with a 3000 stall convertor.  I had just purschased a GM 10 bolt 8.5" posi rear and want to rebuild it and change the gearing.  What would be the best gear ratio to put in it if its a daily driver for the highway use and a weekend warrior for the dragstrip?  Many people have told me to go with 3:73 or 4:10, whats do you think?  Thank you

Answer
Hi Danny:

Both gears are awfully low for street use. Especially if you are going to be doing any highway driving. Of course, fuel mileage will suffer in a big way.

I think that if you're doing bracket racing, your best choice would be the 3.70.  Of course if your racing is head-to-head, then the 4.10 would be better at the track. In either cse, make sure you are hooked up well.

With my road racer, we race at the short and twisty Sebring track, and also at Daytona which features the long straights and only a couple of sharp corners. I change the differential as a unit,  5 or 6 times each season, yes it's a major pain !

By the way, I would have opted for the Ford 9" in your case- - -they're just better.

Good luck at the track !!

Dan Liddy
Sarasota, Florida  

Auto Racing

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Dan Liddy

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Anything concerning race cars, 20 years competition experience, Senior Competition Driver Instructor , car builder, mechanic, welding, fabrication, tuning , engine modifications, set up, suspension design. Specializing in Datsun/Nissan products. Please submit questions about RACE CARS ONLY. No street cars, no video game scenarios Thank you.

Experience

I have been racing for 20 years, I have been the Central Florida SCCA Regional Championship points for 5 years running, and won the championship in my class 2 times. During my first start in the 60's I won many solo awards and the State Championship Drags. I serve as a senior instructor for SCCA, and have taught in Mercedes AMG events at Daytona, and Dodge Viper Days at Sebring International. I have been in the thick of the competition for all of my career. At one time or another I have driven race cars at speeds nearing 195 MPH. It's quite a ride !

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