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Old October 13th, 2016, 01:55 AM
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5500 GMC 5500 GMC is offline
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Join Date: Nov 2013
Location: vaughn, washington
Truck: 1969 5500 V6
Age: 67
Posts: 19
Rep Power: 68
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Default transmission swap

doing a transmission swap and when checking out the calculations for engine RPM to MPH, I am having a problem with the results, here is why
currently the rig has a V6 with a NP 540 5 speed with a 5th gear ratio of 1.00 with 39.5 in dia tires and at 3400 RPM its goes aprox 65 MPH
the calculations I keep coming up with show it would be going aprox 120 MPH ??
does anyone know why this could be
planning on swapping out 5 speed manual to a 4 speed automatic with 4th gear being .75 to 1, this would according to calculations be doing 72 MPH at 1500 RPM is that even possible with a 2000 RPM stall converter
Thoughts anyone
thanks
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1969 5500 351 V6 school bus, mods- 500 holly and duel exhaust
1951 3600 235 L6 pickup
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