As said here, plenty of compression ratio calculators out there on the net.
 
Standard bore is 90.8mm
Standard piston to block deck is 0.5mm (mine came up 0.4)
Standard combustion chamber on an unshaved head is 48cc
Standard head height (head face to bit where rocker cover is bolted on) should apparently be 94.8mm, mine came up 95mm (sierra head).
 
If you are going to take the engine out, get meat taken off the block rather than the head. For best results, get both skimmed so they are dead straight. You can always gain more compression by going thinner gaskets (felpro) without going to far on block or head planing, so factor that in too!
 
I've got a kent FR32 that I thinking of swapping out for a low duration, high lift unit (ie FR30, BF134). If you are keen, send me a PM. The cam is in tip top condition.
 
Cheers
 
Nick

hi nick,
i have rebuilt the engine now fr33, compression ratio worked to be 10.55:1 complete rebuild, all the parts and machining done at Performance Mods in Ossy park(Danny was awesome), Harris Engines for the head.
running the engine in now.

No worries. Great to hear it is up and running. Got my cyl head in at harris engines at the moment. Mark there has helped me with a head for a GQ patrol before and has treated me very well in the past. Can really recommend that joint. What sort of gear have you got in the bottom end? What sort fo carb(s) are you running? Im aim to go a bit milder on mine, 10:1 compression and a torque cam

hey cheese
bottom end crank regrind acl bearings, balanced , re honed, decked block, lightened flywheel etc.
head (already had a lot of porting done, got told to much taken from the ports) head had full service, cut the intake valves new rear profile cc the head, machine head to suit 10.5 to 1
twin idf 44mm webers , pacemaker extractors and new 2 /4" exhaust
its has more torque than the last engine.

hey cheese
bottom end crank regrind acl bearings, balanced , re honed, decked block, lightened flywheel etc.
head (already had a lot of porting done, got told to much taken from the ports) head had full service, cut the intake valves new rear profile cc the head, machine head to suit 10.5 to 1
twin idf 44mm webers , pacemaker extractors and new 2 /4" exhaust
its has more torque than the last engine.