New to restoring!!! Rear end help

[Sketchyfrog]

I recently purchased a 1970 C10 fleetside short bed. It's running a 327 with a performer cam and headers. 3 speed on the floor I believe the gears in the rear end are something like 4.65 gears. My tires are LT315-70R15. I have like a 50 mph top end you can see why I'm concerned lol. The gears are brand new. Is there a rear end that will bolt straight on with high 3's factory or am I pretty much going to have to cut? I want good torque but decent highway speed.

[Fitz]

Originally Posted by Sketchyfrog

I recently purchased a 1970 C10 fleetside short bed. It's running a 327 with a performer cam and headers. 3 speed on the floor I believe the gears in the rear end are something like 4.65 gears. My tires are LT315-70R15. I have like a 50 mph top end you can see why I'm concerned lol. The gears are brand new. Is there a rear end that will bolt straight on with high 3's factory or am I pretty much going to have to cut? I want good torque but decent highway speed.

Just swap out the ring and pinion. $190.00 for the 3.73:1 gear set, $26.00 for a small install kit and $15.00 for a set of shims. Easier than swapping out the entire housing.

[Sketchyfrog]

What's the guesstimation of top speed with 3.73 gears? I had no idea it was that inexpensive to swap gears.

[Mike C]

It's not that inexpensive. You might be able to do it yourself, but it requires at least a few special tools and some know how. You can put it together with trial and error and read the pattern using gear marking compound, but it's slow and go that way.

Having broken nearly a dozen truck 12 bolts unfortunately, I do know how to do it and have acquired all of the special tools...

4.57 would be pretty unusual in a C10 truck, common in a 6 cylinder 3/4 ton though. Check and make sure you are getting into high gear.

I would try and buy a complete used axle housing with the gear ratio you want as the cheapest way to go about it.

You can find gear ratio calculators online that will let you plug in your gear, trans, and tire to calculate cruising speed or top speed, whatever you are looking for.

[Sketchyfrog]

It's just seeming difficult to find a rear end at all more less the right one. I'm cool with a little cutting and welding. Thanks y'all. Just got my new cam, intake and exhaust on. Last drivetrain issue is the rear end but I'll find something I'm sure.