rear end gear ratio change

[Atridox]

1986 Blue Bird on a Chevy c-60 with a 366 gas engine. I want to change the gear ratio to improve mileage. I am having difficulty finding a source of parts. Any suggestions would be helpful.

Thanks.

[lanceferro]

May be changing the ratio of the gears would solve the issue but do take an advice from an expert before changing the ratio..According to me there is no harm and would surely boost n the performance but prevention is better from cure so do follow the expert advice...

[chev49]

One can easily get ring gear/pinion gear kits as well as the bearing kits at the truck parts house. Yours is a common axle. It would probably be easier just to buy a good used highway geared rear axle out of a normal box truck with the same brakes, pull the cover, and check the teeth and install the whole rear axle, if you don't want to change out the ring and pinion yourself. Your ring gear probably takes rivets to put on, and that requires a press. Bolts will work as well.

For the cost of the parts, i would probably just change out the rear axle for a newer good one. fwiw