Has anyone ever come across a site that helps to find common cars with specific gear ratios? For example if I were looking for 3.91 gears for a 742 case what car would I most likely find them... I have a few 742 sure grips with 3.23, I would like to have a 3.91 or 3.73 gear set to install in one of them... with all my money going into the "more importants" I'd like to find a good set in a donor car... thanks for any tips...

There are a few junk yards around with old mopar stuff, just would like a "most likely this car" would be best to check first.. I realize that the car did not determine the gear... but...

 

You "won't". All these such as this are "Easter eggs" They would be optional, and therefore not "expected" in a car. The other factor is "as old as all these old girls are," and especially with 8 3/4, they could have been easily swapped over the years.

Other than that, "heavy" performance cars, like A and B bodies with 340, RR/ GTX, etc and maybe a few pickups or vans which have 8 3/4 in them

 

They have been well picked over the last forty years. Buy new gears and setup a case you have now.