Why would you rip it apart to find the ratios?
Jack the rear up and set it on jack stands.
Put a chalk at 12:00 on the tire and 3:00 on the d-shaft
Turn the tire one revolution; count the number of turns the d-shaft makes
4 + a little bit more = 4:10
4 + and a little past 1/4 = 4:37
4 + a little past 3/4 = 4:88
5 + and a little past 1/4 = 5:29
Do the same in the front; do not forget to lock in the hubs
If it was close enough for NASCAR and NHRA in the old days, it is good enough for me.
