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2 speed to c4

934 Views 1 Reply 2 Participants Last post by  nhrae402
I"m going to change out my rebuilt 2 speed fordomatic witha 70-80 model c4. My question is
What is the differance in RPM at 60 mph? I had a guy from a transmission shop say that the drive gears are the same. (2nd in the two speed is the same as 3rd in the three speed). I don't know if it is the same or not. I might think about swapping out the 3.00 rear end with another.

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2nd and 3rd are the same 1:1 final drive. 1st in the 2speed should be somewhere around 1.8:1. and first in the c4 sould be somewhere around 2.5:1. i don't know the exact # but shoud be close.
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