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1962 Chevrolet Impala 4 door sedan
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Discussion Starter · #1 ·
This car will be driven on the street an I want the rear end an gear ratio to be fast but to be able to handle daily cruising with a 500 h.p. 6.0 ls n.a. build powering this cars rear end. I see plenty of choices so I need help on deciding whats best, thank you!
 

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1961 Impala 2 Door Sedan
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116 Posts
What is the transmission and its gear ratios? Then we can figure out what RPMs you'll turn at certain RPMs... to further that, what's your comfortable cruising speed? My car never goes over 60 for long cruises but someone who takes theirs on the highway at 70+ may want a different setup.
 

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I have a goal of being able to drive my car at highway speeds for long durations, whether it's 40 minutes or 4 hours. So I needed to pick a gear that would target an RPM range on the highway that I can live with, and frequently that might be 80mph. I'd like for my RPMs to be 2500 or less so once I measured my tire diameter, plugged in the numbers and the gear ratio is practically picked for me. For me, a 3.42 or 3.55 was what I needed for my .66 overdrive gear.

Keep in mind that your overdrive in the 4l60 is .70. Many online calculators assume you have a 1:1 transmission top gear. So the number they show you is actually WAY less than what it would be if they factored in the overdrive. For those, you should take their answer and multiply by 1.43)

Why not a 12 bolt instead of a Ford 9"?
 
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