Guys,
The last time I went to check the diff size by spinning the driveshaft, it wouldn't cooperate, and I was doing other things and was in a hurry. I didn't have any help either. So I stopped trying and did other things. Then the other day when I was driving it, I confirmed again that right at 60 mph it's turning right at 3,000 rpm.
So, I figured I would do the math to see if I could figure out what diff it has in it. It is a 727 transmission. So the driveshaft is turning 1:1 with the engine (in 3rd). And my tires are 14". The total tire height is really close to 24 inches.
To spare you all the gory details, when I plug in what the speed should be with a 3.23 gear and 24" tires, it comes out to be 66.3 mph. Not close. When I plug in a 3.55 gear I get 60.3 mph. To my surprise, I think I'm running a 3.55 rear gear. The previous owner said he thought it was a 3.23.
My question is, is there anyone running a 3.55 gear with a 727 transmission. If so, are your rpms about the same as mine? What size rear tires?
Thanks.
7milesout
