think I will change the rearend pig/pumpkin in the 51 chevy 3/4 ton so I can run 15" tires insted of the 17" that it came with. There is a 66 chevy 20 series that is a 4 speed with 16.5 tires on it.What gear ratio would it be and what would the ratio in the 51 be if they are stock?

Is the ratio stamped on rearend? Or do I count teeth when I get them out?

Will this swap let the 216 run down the road at 55 or so with out the motor rpms to high?

thanks for any addvice. Bill


Bill 1951 3/4 ton 5 window pick up
1955 GMC 1/2 ton longbed automatic