Everything I find says that 351c are not adjustable. All I know if i run my 71 mustang down to slight pressure a 1/4 turn bottoms them out. I have bent 2 sets of push rods now. The book says torque to 28 ft. pounds. But that bends them too. Any one have the real way to set lash on a 71 mustang 351c with modified 2v heads.