Thread: Which rear gears for Ford 302/T-5?

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As some of you know, I'm building a 37 Ford tudor sedan. I'm trying to determine which gears to put in my 9" Ford rearend. I have a '69 302 bored to 306 with custom cam, GT40P heads, Weiand Xcelerator intake, Holly 4150 carb (320hp) mated to a T-5 trans. Currently my rear tires are 28" tall but may switch to 29" if I go with 18" rims on the rear. I want the car to be very highway friendly for road trips but also have some punch around town. Here are the breakdown for rpms at 60 & 70 mph with both 28 & 29" tires in 5th gear with 3.50, 3.70 & 3.89 gears:

28" 60mph 70mph
3.50 1714 1999
3.70 1812 2113
3.89 1905 2222

29"
3.50 1655 1930
3.70 1749 2041
3.89 1839 2145


So, if cruising in 5th gear at 60mph/1655rpms, (with 3.50 gears & 29" tires) would the car totally dog out trying to accelerate to 70+ without downshifting? At 70+mph, what rpm level would give the best performance/economy?

I just want to gear the car for comfortable all around performance while still trying to optimize a little fuel economy, you know?

Any thoughts?

Thanks.
Randy