I looking into buying a 1975 Chevy C30 cab/chassis for parts. It has a 350, 5 speed, and dually 14 bolt rear.

What 5 speed is this and is it any good?

It might be a clark 5 speed.... if so its prettydamn tough and is definitely worth hanging on to. All the clark 5 speeds that I have ever seen have a big label plate on the side that says clark and gives the other pertinent info.

l8r

-j-rOd

hopefully it is the 280vo? that has the overdrive 5th gear.

OD or not.... doesn't much matter. The steppings of the Clarks are much nicer than a SM465 for example. With direct 5th, you can adjust your tires size or axle ratio instead.

sm465 6.58 , 3.58 , 1.57 , 1
clark 280V 7.48 , 4.38 , 2.40 , 1.48 , 1
clark 280VO 5.98 , 3.5 , 1.86 , 1 , .80
clark 282V 6.99, 4.09, 2.17, 1.17, 1.00
clark 285V 6.99, 4.09, 2.24, 1.46, 1.00

have you had a chance to check into the tranny to see what it is? Do any of you other guys know what might be a good donor truck or place to try to come up with the clark 280 vo tranny? Might be better than trying to locate a nv4500 that is affordable.