How can I determine the rearend ratio in my truck.

Is there a method/trick to find out?

I don't have any documentation, I don't want to open the pumpkin,

I was wondering if I could jack up one wheel and spin the drive shaft........ or something like that.

any help would be greatly appreciated.

thanks all

brian :confused:

"So many trucks, so little time!"

Vehicle list:
down to 2 now.
1 - 1967 Chevy 3/4 ton LWB 4x4
2 - do I dare say it??? a 61 Ford Unibody