I ran the big Summit cam-224/.465-in a 1968 440 stock valve train. It ran 14.90 @ 92 mph in a D100 longbed truck with no traction. Never had a valvetrain problem. I used to drive it over 100 miles round trip to the track. One time I made seven passes. I pulled that 440 out of a C body that I paid $350 for. Fresh 906 heads and that cam should run low low 14s