Auto Racing: rear end gearing, fuel mileage, buick regal

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