compression with 274cam

DB15

Todays computer controled cars can handle higher comp. ratios along with everything else the engine has built into it. Lessons learned over the years are slow to show up, but there showing up.

The open chambered 360 heds are the biggest problem of the combo. While there fine for certain levels of performance, octane and timing issues cn crop up with cm selection.

The open chamber vs closed chamber is something to consider when building an engine. Closed chambers and a zero deck piston can provided a good quench area. A good quench engine can run less timing, higher octane and larger cams than normally seen in an open chamberd head.

Moper (I think) has a modest build pumping out excellent street power and can get away with a lower octane level than most builds. The Magnum heads are part of this combo.

It looks like (IMO) a similar mech. XE cam would do well with the 273 rockers. Have the heads ported and tell the machinest your lift so he can do them right. I myself would look into a HI lift version. The Xe HI-lift series cams are stout.