rear end axle housing id #'s

[tommie]

is there a chart somewhere that breaks down the id numbers on the axle housing, that determine gear ratio?

i need to find another rear end for my 70' 1/2 ton coil spring and was tring to find a 3.08 ratio. i know you can decipher the axle ratio using the #'s stamped on the axle tube but just can't find a chart....

i need to hit the junk yards to do some searching...what trucks would be the the best to look for a rear end out of (3.08)?
i really don't care if it is a 5 or 6 lug either....

thanks
tommie