So, I put my 36 together twenty years ago, I used a 52 F1 frame, grafted a stock pinto onto the front with 5 bolt, 10 inch rotors and pinto rear springs with a chevy 10 bolt. Had no money, so on went a set of moon discs, and was ran that way for nearly 15 years. Always had a front end shake at exactly 60 miles an hour, feels like an out of balance tire, I just lived with it, I didn't have a lot of car money to jack around with it. I ran cheap coopers on it, blamed them. Years later after losing one of the discs and finding it again, removed them, put on early ford caps and trim rings, still had a shake, so bought new cheap tires again, still had a shake, blamed the trim rings. Fast forward to this year, broke down, bought new torque thrusts all round, put the tires on the truck on the new wheels, still got a shake. Off to the local hot rod, well experienced old guy alignment shop with 70 years under his belt, he drives it, says it's tires, o.k., new good coopers all around, alignment checked all o.k., STILL GOT A SHAKE, although relatively minor. Exactly at 60 miles an hour, although the truck drives like it hasn't in years, an absolute pleasure, the shake irritates me. The only thing left, is the rotors back then were redrilled stock 4 bolt drilled to five bolt chev pattern. Is it possible they aren't perfectly round, does anybody here have experience with the same thing? I'm gonna buy new rotors, the wheels are lug centric, so that's really all that's left, ideas? No, I don't remember where I got the rotors, it was twenty years ago.