Rear axle ratio... Looking for the calculator or suggestions

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Joined
Sep 13, 2016
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Location
Michigan
My Car
71 Base 6 cylinder, and 72 Base 351C
Yet another question! lol

Still gathering parts...  My car is going to have a 351w stroked to 408, with a C4 auto. It has a 9" axle. It will be daily driven during the summer, mostly in town with very limited highway driving. Rear tires are going to be 295-50-15. I am looking for just normal driving, with the occasional quick takeoff from the stoplight when in the mood, lol! I also plan on some sort of posi or limited slip, not sure which yet in particular.

I had seen some sort of calculator on here before, but can't seem to find it now. I'm sure there are others in the interwebs but haven't tried looking for them yet. I have several friends, suggesting anywhere from  3.50 to 3.90's.

Also, any real world experience and suggestions would be great, in fact probably better than a calculator! Thanks, Earl

 
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I am using a 3000 stall converter and 3:50 rear gears, at 60 mph my car holds about 2800 rpm. Even with the big carb it does not get bad mileage and has pretty impressive bottom end grunt. I'm glad I didn't go any higher because I do cruise more than I performance drive!!

 
I am using a 3000 stall converter and 3:50 rear gears, at 60 mph my car holds about 2800 rpm. Even with the big carb it does not get bad mileage and has pretty impressive bottom end grunt. I'm glad I didn't go any higher because I do cruise more than I performance drive!!
I am running a 3000 stall converter with my 3.73's also. I am very close to the same 2800-3000 RPM at 60-65 mph. but who knows how accurate my speedometer is and my rear tires are pretty tall. I get pretty bad MPG. I was at 7-8 MPG but with new cam and tuned properly im up to around 10MPG.

 
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