255/70 is stiffer. i bought those, gotta build new shock mounts though. i figured heavy truck with big block those would work better! also wherabouts are you looking at those? i bought mine from shockwarehouse.com they were $90 each and only $17 bucks to ship all 4 thats for the 14" travel ones too. they showed up 3 days later shipped direct from bilstein in california.