I have a 1977 Ford with mechanical flat tappet cam from the factory. Its a stock car and runs great. I adjust the lash once every 3 years, no other problems. You just need to adjust it on hot engine.
solid flat tappet and solid roller are not the same...flat tappet lifters don't have a roller wheel and axle which absorbs the brunt of the force imparted on the lifter during actuation.
