C50 5 speed?

[lexadmn]

If I am wrong, hopefully someone will correct me.
I don't think a 5 speed will do you any good for achieving a higher "mph" as the final drive is 1 to 1, just as it is on 4 speeds unless you find something like a Clark V0 overdrive 5 speed - which the final drive is 1 to .8, or another form of overdrive.

[factorystock]

Originally Posted by lexadmn

you find something like a Clark V0 overdrive 5 speed - which the final drive is 1 to .8, or another form of overdrive.

I agree, the Clark 280 VO was the optional overdrive back in the day with the .8 overdrive, which IMO, would be perfect. Modern overdrives, like the NV, are more common, but are around .7 overdrive ( larger step down in rpm ). Like ky-donzi mentioned, the 1 ton 3500HD version has the much needed parking brake drum. Make sure the NV4500 is a good unit first, many have noisy bearings that need a professional rebuild.