Stiff/fresh bushings can help with the wheel hop problem, but they cause others. Because the upper and lower control arms aren't parallel with each other (that triangulation also serves to locate the rear axle side to side), any time the axle has to tilt with respect to the body (like in a hard corner) then the control arms have to "twist" at their ends to allow that to happen. If they can't twist there, then they bend -- or break -- and "bad things happen". With the factory rubber bushings, it's the bushings that allow enough give for that to happen (but when they wear they also contribute to wheel hop). If you really want to fix both problems once and for all, replace the factory upper/lower control arms with aftermarket ones that use some sort of sphereical joint on the ends. This takes all the front to rear slop out of the joints and cures wheel hop, yet they allow the arms to freely "twist" like they need to in corners. Another bonus with them is if you get at least uppers that are adjustable, now you've got a way to adjust your driveline angles to get rid of vibration and stuff.
I'm running chromoly Spohn upper/lower arms on my 69 with their "del-sphere" ends. Love 'em. There are others out there.