4.375 x 4.375
10.85 compression
Ported TrickFlow PP 270's
.714 tight lash solid roller (262@.050Int/268@.050Exh)
.035 quench
20 degrees initial - 34 total in by 2800. Advance set to not start coming in until ~1600rpm (probably switching to locked distributor this summer)
180 stat
3800 stall
4.30 gear
3800 lb Coronet

I run just regular 93 pump gas and have had no issues with detonation so far. No signs of it on any plugs, and nothing that was audible. I did sweat the details and made sure I knocked the sharp edges off anything in the combustion area and also polished the chambers to fight carbon buildup. I am a firm believer in a tight quench motor. My last build ran .027 piston to head clearance. On teardown I could see the slightest hint of a witness mark on the intake side of a few pistons so I opened it up a little on my next build. I didn't see any hint of collapsing the rind lands so I figure I was ok but still wanted a little insurance.

I hope this helps.