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Differential Pick

CafnutS

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I will like to say first, thank you for all the help you guys have provided me.

I purchase a Edelbrock 2086 TOP END KIT which will produce 421 HP with 417 Torque. Additionally, I purchased from Silver Sport Transmission an A41 Automatic 4 Speed transmission. I would like to know which diff ratio would be best for state to state driving and cruising. 3.23, 3.55 or 3.91.

Once again, Thank you.
Ed
 
Is 4th gear overdrive? and if so what is the reduction?
 
How tall are the rear tires?
 
4sp n 400+ tq, state to state driving and cruising, go 3.23. Plenty of torque to spin them if you want. If you're racing, that's another matter.
 
I like a combined final drive in the 2.75 range for a highway cruiser with appropriate built engine (camshaft etc.). It's all about the complete package.
 
I will have to ask about those items you mentioned. However, the A41 Ratio are 3.06, 1.63, 1.00, 0.70.
0.70 would be overdrive and a fair amount at that.
Maybe something like a 3.91 gear would work well
 
Let be more specific, how tall are the rear tires? 28, 29, 27 inch?? That makes a difference.
 
Use this rpm calculator. Determine what kind of highway speeds you'll be driving. Then determine what kind of rpms you want to be turning at those Highway speeds. All that's left is to figure rear tire diameter and diff ratio. W a bone stock 2bbl 383 and 2.92 gears, my car would broil the back tire without power braking.
https://www.reillymotorsports.com/speed-tire-rpm-calculator.html
 
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