The Stovebolt Site Forums The Shop Area Driveline 1957 3200 driveabilty on the highway?

I just completed a frame off,of my grandpa's 1957 truck he bought new. It hadn't ran in 30+ years. It is bone stock with the 235 6 and the 3 on the tree, every thing has been rebuilt including the rear-end (bearings- bushing etc.) The truck is comfortable to drive around 30-40mph ,It sound and feels like it wants to jump out of it's skin at 50-55.My top speed I would like to drive it is 55mph. any suggestions on rear-end ratio to give me the 30-040mph ride and feel at 55 mph? I am not a super tech so dumb it down for the rookie please.

The easiest way to achieve this would be to swap in an overdrive transmission, rather than do a rear swap. If you go with the SM319 overdrive, which was a factory option, it is a direct bolt in. This is a common transmission to find, though you may have an easier time of finding one from a '55-'57 Chevrolet car, which isn't a problem as they are essentially the same as the truck version.
I did this swap on mine, and can easily run 75 on the highway.

a stock long 1/2T should have a 3.90 rear and should be capable of 65 or better, although noisy - you won't find any gearing that will make it sound like 30 when it's going 60, but the 3.38 rear gears from Patricks would help by lowering the RPMs, or the optional 3 speed overdrive if you can find one

Bill

Thanks longbox55, question on the overdrive transmission? Will it bolt in with out any modification to the drive shaft?

Thanks red58:
I will start looking at the two options you suggested.
As you said "if you can find a overdrive transmission" What is the common asking price for one ready to install?

asking price might be anything, depends if the seller thinks it's scrap metal or gold plated, count on around 2-300

Bill

I have done numerous 3 speed OD conversions for Stovebolt members and others. I have some rebuilt units available.
There are other parts that are recommended for the conversion to include a pull cable, relay, kick down switch, and wiring loom. If you are in the So Cal area I may be able to help you out.
I do not ship.
Fred

If all you want to do is 55 mph, just leave it as it is and get used to how it sounds. I have been daily driving a '59 1/2 ton, 235, 3 speed with 3.90 gears since April and the truck does 65 easy. 55 is certainly no strain at all.

That sounds about right.

If you are trying to maintain the stock look, the 3 speed overdrive is the way to go. I have a 58 Suburban that I did the swap in about 6 months ago. It was an excellent change.

As far as I know the three speed and rear end in the truck were stock/original when I got it. In third gear I was running 3,000 RPMs at 55mph. Like you, I thought it was too high for comfortable driving. It wasn't that the truck wasn't capable. It could run like that all day long. The problem was I couldn't hear myself think when driving and it drank the gas.

After the swap, it runs 2100rpms at 55 and will run 70mph without any trouble. The mileage is better as well.

I bought my tranny on eBay. It came from a 67 chevy C10, so it is a Saginaw with the synchro 1st gear. It is rumored to be a stronger transmission and more desirable. I paid $535 for mine. That may seem like a lot, but it is 100% complete. It came with the complete wiring harness including the relay, kickdown switch, governor and solenoid. All I had to do was acquire a new yoke for the front of the drive shaft. The later model transmission had a different spline count on it's output shaft. It once I got the yoke changed, it was a simple swap.

Anyway, in my opinion is definitely the way to go. You get to retain the 3 on the tree tranny but also get the benefits of an overdrive. It makes for a whole different driving experience.

If you decide to go that way, shoot me a PM. I've got a few lessons learned that may help you.