The Stovebolt Site Forums The Shop Area Engine Shop 55 second series tranny

I've got a 1955 Chevy 3800 with the 235 and 4 speed on the floor. Are these transmissions worth keeping? I'm sure as being the 1 ton model it was a work truck and not overly quick but I'm curious how it would do. Thank you

Caleb

"worth keeping"? as in driving it with one, or stashing it under the work bench?
pretty much the same as the 3 speed, with a granny low if you want to climb a wall, the same as it would be in a 1/2T, the difference with the 1T is the poor rear end gearing

Bill

I meant worth keeping as in driving with it, otherwise going into storage haha I've also got a 63 c10 with a 3 speed on the floor but the lack of 4 gear is killer on the faster roads (and for gas) which transmission/rear end combo might you recommend with the 235 in this big ole rust bucket

Young Gun,

All transmissions (unless they have Overdrive) have a 1:1 high gear. This means your 3-speed and 4-speed will perform the same once in high gear. This is also true for the automatics like the TH350 and TH400. So 3000 engine rpm gives the same results with any of these 1:1 transmission. If you want to go faster you need to go with different gears in the rear, run taller rear tires or go with an overdrive transmission.

Your 4-speed should be the SM420 which is a bullet proof transmission, Chevrolet used it for almost 20 years. Unless there's something wrong with it I'd leave it in the truck and drive it like a 3-speed using 2, 3 & 4 only...that's the way I use mine.

Mike B

The lack of 4 gear is not the killer on the '63. It is the rear end gears. Same as the 1-ton, as Bill mentioned. Both the 3 and 4 speeds in our old trucks have a final output of 1 to 1.

It appears you are used to modern transmissions with overdrive. An overdrive would be an easy install on either of your trucks.

Thanks guys, I'm not a transmission guy so this helps a ton. And Mike thanks for the info on my 4 speed, I'll be sure to keep it!