Most of all Buick GN guys run under 26 degrees total timing,For pump gas & no methanol injection.
Read up on the Buick GN forums.
I have said it before,,, if you have a decent quench area you could run say 9 to 1 compression on pump gas,,,, now,,you can have 8.2 to 1 & have it detonate like crazy because you have no piston quench & or sharp edges on pistons or chambers.
That being said, you can get some sort of quench ,even if it is just on the edges around your piston, & yes it will help supress detonation.
Sure your compression will go up, but you can open up your cylinder head chamber.
I have a 250 Chevy w/307 flat top pistons w/four valve reliefs.
Small 194 head milled to 50 something cc's (can't remember right off), but w/that head & pistons I had 12 to 1 compression,220 cranking compression, ran on 91 octane,no detonation.
Pistons are .000-.003 postive deck height,decent quench.
Switched to big chamber head, sunk the valves a bit, unshroudeded & opened up the chambers to 80 something cc's (can't remember right off)
Had 8.5 to 1 compression & a Paxton super charger,still no detonation w/8-9 psi boost pressure & no intercooler on 91 octane.
Total timeing w/supercharger was about 30 degrees total.
So 12- to 1 to 8.5 - to 1 w/out changing pistons,just changing heads & opening up the chambers,not bad.
MBHD
