HMMMMMMM, got to thinking about it , I'm gonna get the severe duty springs for the f-350 dually like ya said Larry, prolly be the only time I ever have to do this again so I may as well get the better spring and it should help when I pull my camper this coming up season. it's the CC844s , they have a Load of 1759 and rate of 629, seems to be the better one.
I measured the diameter of my friends 2wd f350 spring it was 3/4" mine is 5/8". Go figure, thanks for making see straight on this one.

Mike