The Stovebolt Site Forums The Shop Area Engine Shop cruising speed for a 61

I have a lead on a 1961 without a title. I want to understand if the 4 speed and rear end will get me a good cruising speed (~70mph) in my 52. Is it an easy swap?

2 speed, 3 speed, 4 speed all have the same final drive gear: 1 to 1, and have no effect on top speed or any speed in high gear. Only overdrive, or an overdrive transmission (T5, 700-R4) does this.
The axle will only help if it has a numerically lower ratio than yours, such as 3.55 vs. your 4.11, etc.
What is it?

pretty sure a 52 has 4.1:1. I was hoping the 61 had 3.55:1.

If correct, what is the cruising speed?

The '61 will be 3.90:1 if it's a half ton and it came with a manual transmission.

not much better then? I an get it cheap I think. It has been close to a fire, broken glass and blistered paint. But if I can't use the parts then just another project.

The '61 center section is a direct bolt in to your '52 housing.
(if they are both half ton)
Which will get you a little bit faster gear and an open driveshaft as well. You will need to weld the spring pivots also.
The gear change will gain you about 3 mph at 2500 rpm.

I will go look at the truck and see/hear it run.

A 61 with a 3:90 rear axle will do 70 miles an hour, but not very comfortably. 60 miles an hour is a pretty good cruising speed for mine, but I usually have to go faster so I don`t get in the way.