I'd agree with Bill. Dont make sence that a smaller one would be better than a bigger one. My 47 2 ton uses an 1 1/4" one and school bus chassis and fire trucks used an 1 1/2" one. If it wasnt needed then I'm sure that the factory would have put tiny ones on in the first place.

Jeff
1947 Chevy 6400 2-ton
In the Gallery
1953 3/4-ton
In the Gallery
It was fun while it lasted