63 C20 stock I6 which rearend should i look for

[defgone]

nearing the process of swapping out front cross member and rear end....i am leaving the stock I6 230 (will add offy intake, holley 4 barrel, dual exhaust manifold)...my questions are:

what gearing is my stock 1963 C20 rear end?
what gearing should i look for to be able to go a little faster but maintain decent gas mileage??(trying to be able to get around town a little quicker and occasional cruise at 65-70mph)

would a 308 rear from a mid 70's c10 be good??

[blackedoutharley]

A 3.08 rear from a late 60's c10 would be better.

[Captainfab]

The original rear end in your '63 C20 likely has 4.57 gears. That is the most common gears in the HO53 rear end that I have found. It sounds as though you are converting your truck to C10 running gear.Is that correct? If so then as blackedoutharley said a ''63-'72 12 bolt from a C10 would be a bolt in swap for your C20. The '71 and up are goping to have the 5x5 wheel bolt pattern. If you go with a '65-'72 rear end, your original '63 panhard bar will be too long. You will need one from a '65-'72. You could get a rear end from a '73-'87, but you will need to cut off the leaf spring perches and shock mounts, and weld on the trailing arm mounts and a panhard bar mount. You could cut the one off of your current rear end and weld it onto another.

[defgone]

yes i am looking at switching pretty much everything to a c10....parts seem to be a bit easier to come by(that and i'm lowering it for cruising)...i am putting on a front crossmember from a mid 70's c10 with 5 lug rotors and thought might as well stick with the the 5 lugs in rear making rim selection a bit easier....so the truck i'm getting the front end off of also has a stock 308 rear and was trying to see if it was worth it....i also have a line on a mid 60's camaro rear end that i am told might work as well (i think it is 355 or 373) the leaf to spring mounts is not a huge deal because i'm going to mount bags on the trailing arms anyways so there will be fabrication going on anyways....

[Captainfab]

I would use the rear end from the truck. That way you have the 5x5 bolt pattern on both the front and rear. The Camaro rear end will have the 5 x 4.75 bolt pattern.