The Stovebolt Site Forums The Shop Area General Truck Talk axle ratios??

What rear end ratios were available for the 60's C-10?? I have an Olds 455 W/TH400 shoe-horned into my 64 stepside. The tranny shifts fine, but it is in third gear by 40MPH under normal driving, and is pretty wound up by 60 (don't have a tach in yet, so I cant give accurate #'s) How can I tell what I have in it now, and what do you guys recomend I put in it?? I would really like to drive it on the interstate, but it is kept in town for now for obvious reasons. Thanks in advance.

If you have a half ton, you probably have 4.11 gears (at best 3.73s).

I could ride at 55-60 all day with my 3.73 gears when I had the stock 3 speed transmission. 65 was pushing it, for extended driving. And the absolute top speed was around 80-85.

If you plan on doing a lot of highway cruising then you need to change to either an overdrive transmission or a 3.07 (or numerically lower) rear end. I think the overdrive transmission is the best solution. You keep the same rear end, have better low end gearing for "off the line" acceleration" and end up (usually) with lower cruising rpms on the top end.

-ftyler

I just checked the axle ratio on my '66 C10 shortbed fleetside. Its a 3.73:1. Look on top of the axle tube on the passenger side close to the pumpkin. There is a letter code stamped there. Mine is "HA". Now go here to see what the codes mean:

http://www.americanclassic.com/paint_test.asp

How bad will the 3.07's hinder my acceleration?? Or would it be possible to bolt a 700R4 to the olds BB?? I would rather swap the rear end from another truck, but which one?? I have never messed with rear end gears, is it tough to get them meshed correctly??

I have a 700R4 mated to a GM crate 350 motor and 3:73 rear end in my '66 shortbed. It seems about perfect for cruising, about 1800 rpm at 60.

Steve

For my money,it's better to replace the whole rear end.Usually just a matter of changing the spring pads,and sometimes building a set of shock brackets. (and bleeding brakes,again.)
I have a 3.08 in my GMC;it's theoretically good for something like 129 at 4,000 rpm. Of course,it takes a lot more horsepower than I have to push a barn door up to 129 mph. I run about 1500 rpm at 60 mph.(Thanks to the LT235/85-16's)
I guess taller gearing is better-you can always downshift if you run out of power,but what can you do if you run out of rpm?
James

if you want an automatic overdrive behind an Olds, find a 200-4r and have it built to handle the torque. they are drilled for BOP and Chevy bolt patterns

sorry im really new to this stuff and i might sound like an idiot but anyway, is an overdrive transmission manual or auto, or either??

It's any transmission where the final drive ratio in the transmission is lower (numerically) than 1:1.

and that gives you better gas mileage right? and can you get a manual transmission with an overdrive gear?

a 700r4 auto trans will bolt to your engine with an adapter.the 200r4 is a lighter duty auto trans that will bolt to your engine.if you want a manual the only factory trans strong enough is the t56 six speed from the later camaros.this will also need an adapter.there are aftermarket manual trans that may bolt to your engine.if your well off you can get an overdrive that will bolt to the back of your transmission.