RPM?

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Mar 2, 2022 | 12:59 PM

Prionus

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Mountain Pass

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RPM?

82 F350 C/C 351W T18 4.56 gears in diff. What kind of RPM am I running with this setup at 45 and 55 mph? It sure seems to be screaming at 55.

Mar 2, 2022 | 01:17 PM

raytasch

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Joined: Jun 2004

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From: W. Central FL.

You forgot to mention tire size. With tire size, actually circumference, you can calculate rpm at any given speed with one of many online calculators.

Mar 2, 2022 | 01:36 PM

Franklin2

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From: Virginia

With 4.56 you will be screaming at highway speeds. Most people don't even like 4.10 gears. That's why I put a overdrive trans in my truck, it has 4.10's in it.

Mar 2, 2022 | 02:23 PM

Prionus

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Mountain Pass

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Quote:

Originally Posted by raytasch

You forgot to mention tire size. With tire size, actually circumference, you can calculate rpm at any given speed with one of many online calculators.

I should have known that. Tires are 235/85/16.

Mar 2, 2022 | 03:12 PM

FuzzFace2

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Joined: Nov 2015

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From: Angier, NC

At 55 MPH I got about 2700 RPM
At 60 MPH I got about 2900 RPM
They just dont look right to me, little to low.
All from the site below

https://www.garysgaragemahal.com/calculators.html

What would have been nice 2 years ago would have been to get Advance Adapter's Range Splitter over drive but they no longer make it