Help with 340 compression + cam change

just a guess here
but an observation on recommendations

Mike Jones-
280/280, 224/224 @ .050, with .495"/.495" and 108 LC, plus he recommended limited travel lifters.

Howards-
267/267, 220/220 @ .050, with .506"/.506" also at 108 LC.

I would guess that jones is using a .842 profile and Howards a .904
you would have to see a complete profile to really know
with a high compression motor the longer duration might work
but with a 8.5 the shorter duration would be much better for dynamic compression
now jones could be using a profile with the nose rolled over limiting lift
a lot of heads can't use more than around .500 lift anyway which both of these provide
but how quickly they get to the high flow area of the head is what matters not just peak flow for a very short period of time/ duration
I know for a fact that jones 256 .904 cam has more area than any other 256 cam that I tested on the cam doc (way back when) but over 50 % bigger than the much longer DC 260 at .275 cam lift
you are better off with a solid lifter cam
I know jones has some excellent solid .904 grinds and his inverse radius rollers can't be beat
especially for low compression builds as you can get equivalent profiles to flat flank with much shorter seat timing
measure twice- cut once