First setting the tip clearance has nothing to do with the correct tip to roller geometry, 302 pedestals are too long tip to fulcrum for a 3.0 without proper shimming and changing the length of the pushrod accordingly. Second, I hope your running some kind of pushrod guide as was noted earlier these rockers are not self centering, the originals while not truly self-centering are trapped by the fulcrum bearing and limit the side to side walk of the rocker.
If you want to do it right, your going to need an adjustable length pushrod and shim / adjust to get the rocker tip into the center of the valve, and for the travel of the tip to be centered on the valve throughout the movement of the rocker, otherwise it slides instead of traveling up an down as it should.
While setting up a valve train is not black magic, there is an art to doing it correctly and anytime you change a ratio on a rocker or other valve train component its definitely not a bolt on and go item, otherwise you will see guides & valve stems trashed in a very short time.
I wasted a ported set of heads and lightened 5 angle ground valves in about 5-6K miles on a 3.0 trusting a set of pedestal mount rockers that were highly advertised here and another Ranger forum as true bolt-ons. When I brought up the issues to the seller, the kits immediately disappeared and were no longer for sale. I knew better than to believe the hype, but did not do the geometry checks as I should have.
So I developed my own Roller rocker kit, they are not noisy, the motor revs so fast its hard to believe its the same motor. I run 1.75 ratio, guides, hardened pushrods, beehive springs that are almost a 55% increase in tension over stock springs, and comp cams anti-pump lifters for a 302. This setup has been on this motor for almost 25K miles, there is no wear at all on either roller or valve tip. All this was done after adding the Whipple and blowing the valves off the seats at anything over 14 psi.
Not trying to be a know it all, but I have been in your situation, and had to fix someone else's mistakes that cost me $$$. Your heading down the same road, just a word caution to consider
JP02XLT