I need to know RPM ranges

Lowhound · Apr 26, 2014

I'm in the process of redoing a 70 Bee. Equipped with a 383 with a 4 speed transmission. In the past I ran a 410 gear in the rear end & the best that I can recollect the motor would turn roughly 28-2900 RPM at about 60MPH. Like I said the best I can recollect, if I'm wrong feel free to correct me. I have a 355 rear gear that I am thinking of using but I would like to know how many RPMs I will be turning at 55-60 MPH. The Bee will mostly be a cruiser but probably not too long of trips. However I would still like to have decent take off.

Rocketman · Apr 26, 2014

Lowhound said:
I'm in the process of redoing a 70 Bee. Equipped with a 383 with a 4 speed transmission. In the past I ran a 410 gear in the rear end & the best that I can recollect the motor would turn roughly 28-2900 RPM at about 60MPH. Like I said the best I can recollect, if I'm wrong feel free to correct me. I have a 355 rear gear that I am thinking of using but I would like to know how many RPMs I will be turning at 55-60 MPH. The Bee will mostly be a cruiser but probably not too long of trips. However I would still like to have decent take off.

I have a 440 4 speed in my GTX that at 3k is running right at 60 according to my motorcycle riding friend that was behind my last Saturday. I have a 3:55 Dana.

62 Dart Convertible · Apr 26, 2014

Remember tyre dia has a big effect and can affect comparisons. Use a calculator, like -
http://www.csgnetwork.com/multirpmcalc.html

bigblock · Apr 26, 2014

Go with 3.23s. Best of both worlds.

451Mopar · Apr 26, 2014

It depends on the tire height. I just took the 4.10's out of mt '69 Coronet and put 3.54:1 gears in.
I have 255x60x15" tires which calculate out to 27.05" tall. with 4.10 gears at 60MPH, the engine RPM should be about 3,055 RPM.
With 3.54:1 gears at 60 MPH, about 2,638 RPM

Dutch Rebel · Apr 27, 2014

This is a nice tool too use
http://www.mopar.nl/tach23.swf

Lowhound · Apr 27, 2014

Thanks guys, that calculator really helped me make up my mind.

Garys1969RR · Apr 30, 2014

I drove a 67 Satellite from Ohio to Colo, and at 3000 RPM I was at 79 MPH (according to the GPS) with 3.23 gears. The speedo was indicating 90 plus. Thought the engine was revving too high, so went to 2.76 gears I had removed from my RR. That is just right. Now the speedo is only 3 MPH off. It has 14" Cragars on it, which requires a lower (numerical) gear to keep the RPM down.

I need to know RPM ranges

Lowhound

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Rocketman

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62 Dart Convertible

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bigblock

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451Mopar

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Dutch Rebel

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Lowhound

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Garys1969RR

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