Stop in for a cup of coffee
The compression get real important when picking cams.
Cams can bleed off or build pressure depending on when the intake valve opens and closes.
Mopar's rod and stroke combination results in less piston time at the top and more at the bottom than (most) other brands.
IMO this means finding someone who understands that when picking a non-mopar cam.
A/J may be off the edge (pun intended) but all that Wallace calculator stuff he posts I think is valuable.
I've bought two 340 engines without knowing the real compression ratio. I will not make that mistake again with the engine sitting on stand now!
And that first one, from RHS (CC's sister company atthe time), needed valve seals a valve job the first couple years I owned it. :(