VCCA Home Forums TECHNICAL - GENERAL Mechanical - Engine, Trans, etc 4.57:1 rear end

I have a 3600 1949 Chevy 3/4T with a 216 motor and I believe it has a 4.57:1 ring and pinion gear. It's a 4 speed transmission. I can climb telephone poles in the granny gear, but all I can get is 40 MPH winding it out. I am in the process of replacing the 216 with a 1954 235 motor and would like to get at least up to
50 MPH to keep from ticking off everyone behind me. Two questions, will the 235 get me up to 50 and , if not, where do I find a 4.11:1 or 3.73:1 rear axle ratio that will get me up to speed. Are these ring and pinion gears still available or do I need to find an axle from a later model 3/4T truck?

Scott, try Patrick's, they can help you.

http://www.patricksantiquecars.com/

Rust:
Patricks is in the process of getting something together for the 3/4T like they have with the 1/2T, but they haven't got the necessary ring and pinion gears made yet and don't have a definite timetable. They're telling me to find a 3/4T in 1946-1972 vintage, but I was hoping to avoid going to a boneyard. I guess I was hoping for a simple ring and pinion kit to install and be done with it.

I would just wait until they get the right part and as for the people behind you, don't worry about them. They should take into consideration that you are driveing a vintage truck and enjoy looking at it. Just give them the peace sign when they are giving you the other sign...Oscar

Rust:
You may be right. I like you're style, but it would sure be nice to drive somewhere near 50-55 MPH or at least not feel like the motor is going to blow up.

I guess I don't know, so I'll ask just to make sure. I PRESUME the truck rearends / gears are bigger than the passenger cars of that era.

Presuming that's true, I guess you can't just do the old "trick" of putting a '54 power glide 3.56 ring and pinion in to replace the 4.11's. Like the swap done in 40's cars so they can be driven faster and not rev up the engine so much at 60-65mph, etc.....

I suppose that won't work because you're talking about a 3/4 ton truck.

Bill.

When those trucks were new they would do about 70 MPH in high gear.Thats around 3800 RPM's.At 50 MPH they sounded as if they were in 2nd gear due to the large fan blade a truck has,poor firewall insulation and no cloth upholstery in the cab to absorb noise.They would cruise all day at 3000 RPM or about 50-55 MPH.
The later trucks had a 4.10 and 3.73 ratio.The 3.73 was used with V8 engines and automatic transmissions (not on all).
With a 4.10 and the large 7.00 X 15 tires (7.00 X 17 were optional) 3000 RPM equals about 60 MPH.
With a 3.73 3000 equals a little over 65 MPH.
Your best bet is to pull the center section out of a later 3/4-/-1 ton truck from the 60's and up..Would be a lot less work than changing the ring gear and pinion in your present set up.

Chevgene:
When you say pull the center section out, are you talking about the pumpkin?
Scott
P.S. 70 MPH in my truck would be a thrill ride...or suicide.

Yes, remove the center pumpkin.
I used to drive them that fast when they were new.I made dealer trades for the dealer I worked for.
Our 1/2 ton parts truck would do 80 on the level - had it up to 85 once on a down grade.