I'm new to the modificaiton world. I have some basic questions about differentials and clutch modifications.

First, I'm not completely clear on differential ratios and what the numbers completely mean. I have a Dana44. Could anyone shed some light on it and what the difference is between that and let say a Dana60.

To piggyback on that, I am looking into putting 35" tires on my truck and what, if anything, should I do in regards to my rearend. Always wanted to pick up on a hobby like this, and now I have the chance, but definitely need to learn a little more before I try that. What other considerations do I need to make before changing the tires?

Also, I'm currently exchanging my 360FE for a 351W in my '73 Ford F250 Highboy 4x4. I would like to make the clutch a hydraulic one. Any suggestions or tips in doing so?

Sorry for the basic questions, but would definitely appreciate the help.

 

Welcome to FTE. Research is a good idea before making changes.

DANA axles. The bigger the number, the bigger the axle. That's the short version. More info:

Axle Identification Chart


35" tires. You need to determine your existing ratio and see if it's going to work with that tall of a tire. You may have to regear. You should be ok axle strength and clearance wise. There were axle ratio tags on the axles, and an axle code on an info plate on the door jamb when new, so see if anything is left of those. With a 4x4, my guess is you already have 4.10s so you are probably ok here.

360FE to 351W. Different engine series, requires a different bell and clutch. If you are getting some stock used up wheezer 351w from a scrappy, you might as well keep the 360. The 360 can be converted into a 390 or even up to a 445 if you want a firebreather.

Hydraulic clutch. You can find hydraulic clutch set ups in Fords from about '84-'85 on. Then you will have to adapt them to your vehicle. Is your clutch linkage in poor condition, beyond adjustment or repair?

Summit and other suppliers have hydraulic clutch kits. Hydraulics are also found on F and C series trucks from at least '58 to ??? so those could be candidates for adaption as well.

 

Thanks for the Axle ID chart. It helped me a lot. I'm not sure about the 4.10, what does it mean in regards to different ratios? IF I was going to change the ratio, what would I want to look into?

The engine is a fuel injected late 90s. I already found a bell housing for the engine. Can I use the original clutch system off the 360 or is there something else I need to do in order to make it work. I didn't think that I was going to be able to use it so I figured I would go the hydraulic route. Thanks for your help.

 

Will the bell and the lever etc accept your current linkage?

Or is it already equipped with a hydraulic slave set up?

As for ratios, 4.10 means in your current high gear, 4th, which is direct drive (1:1), the engine turns 4.10 times for every 1 turn of the drive wheels.

The taller tires will result in lower engine rpms at any given speed, as the tire is the final link in the overall "ratio" of the vehicle. Thus, if you taller tires result in RPMs too low for the engine, you have to regear to compensate.