Quote:
Originally Posted by ab positive bulldogs
Be careful I have a stock 351E with the Dana 60 and 4.10 gears I installed a tach to make sure I am not hitting redline on the freeway and I am at 3100RPM at about 45mph with 33" tires
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Quote:
Originally Posted by 66birdman
I am not saying this for sure but your tach may be off. According to every calculator and formula i have found with that set up you should be running about 1850-1900 rpm with that set up
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I agree! maybe his tach and his speedo? Most 33's are closer to 32" but that is still off.
Quote:
Originally Posted by adamfgarner
for what it's worth....I have the sm420, Dana 4.10 gears and 265/75/16 tires on my 1500 series...my tach reads just at 2000 for 40 right under 2500 at 50 and close to 3000 at 60...there are several calculators available on-line though there will be discrepancies as your tires get smaller with use and are slightly different from maker to maker...I am doing my first mileage test with this drivetrain...will post the changes when I do the 3.54 swap....as for my research I have found that 3.54 is as low as the Dana 60 carrier will accommodate...the 3.31 gearing might be a Dana 44 or other model???
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Going by the listed diameter for your tire you are fairly close. I did the math and got 1778@40mph.
With 265/65/17 my speedo/rpm read the same as yours but my speedo reads about 10% slower than actual speed.
My buddy that told me about the DANA 60 3:31 owns a diff shop and he was surprised to see them listed also. I am trying to get them ordered but he is a busy guy...