bumper questrions

hey, got a couple of questions for y'all. getting ready to start rolling on my front bumper, gonna be bunch of tube. when cutting through it, what should i look for to indicate i'm going at a good speed? secondly, i'm wanting to try and incorporate a steering box brace of sorts. i went out and looked tonite, but i didn't see the cast aluminum brace thats shown on c-roks page. is that a later model thing? (mines a 93) would it be sufficent to simply make the bracket bumper large enough to cover the holes for the steering box bolts, and then replace those bolts with slightly longer grade 8's? or should i get something on the box side. the bumper will be attaced with 3 grade 8's on driver side, 4 grade 8's on passanger, and 3 stainless on each side in front through my custom radiator support. all 1/2" stuff. i plan to get up to about 40" tires eventually. thanx for your help guys