My HP 383, is absolute Zero Deck. Was well above static 10 to 1 with shaved 906 heads. I totally understand the cam has some influence for real compression #'s.
The 292/509/108LSA Purple for sure! But advanced 4 degrees and the cylinder pressure goes back up!
Before using some thicker Head Gaskets in 2014 to be able to run REC90 going forward, I had fuel buy issues!
Today all smiles and a REC90 diet!