I am going through what i am going to due. Lost a flat tappet cam due to indy rocker failure. Heads are 360-1 springs are 939 comps 140 seat 415 over nose. pulled engine cleaned and put short black back together. I already have a new ft cam. First FT. I never lost what a huge PIA. Years ago had a bracket car duster 3250 446 B1BS heads car ran ran 9.70s in good air usually 9.90 with flat tappet Racer Brown. Switched to a roller cam picked up less than .05. cams were vary similar 272 @50 roller had over.100 more lift. I alwyas ran 150 seat 410 over nose is that to much spring.
I gotta check my notes but man 415 over the nose sounds high to me for a solid cam
It's getting close. I've run that high but you can't let the idle speed get too slow, you can't screw around getting it cold started it if sits for awhile and you have to be real careful about floating the valves.
I can't explain the last one...but I know from experience when the spring pressure gets over about 360 on the seat, that an over rev or banging the engine off the rev limiter it will tear the nose of the cam much quicker.
