Camshafts and Compression
Well ok, here it comes;
I grossed your numbers up to a conservative 280/288/108 in at +4 and got;
68* overlap, an Ica of 64*, which at 10.7 Scr, the Wallace spits out;
@900ft; a Dcr of 8.64 and pressure of 176psi
@300ft; a Dcr of 8.64 and pressure of 179psi
IMHO, you need a new compression tester
My 367 has run at up to 11.3 Scr with an Ica of 61*, and Wallace Pressure of 192psi@ ~9.23Dcr.
This runs on 87E10 @34*@3400 rpm, with alloy heads.
There are reports of several FABO members running their strokers at up to ~205psi albeit on best pump-gas.