cutting about .050" will increase compression ratio about 1 as has been said. good for about 3-4% more power and torque. refaced lifters sounds very old school and questionable. refaced flat or convex? refaced a little or beyond the hardened surface? will your copper gaskets be in the correct hardness range ?
MHR, Good point about the lifters, I may just buy new ones (solids), they range in price from A$140 (Mexican made Elgin 'dumbbell' OEM style) to $345 for Crower.
I watched he guy do the lifters, he knew what he was doing, he hardly took any off, just the absolute minimum to get the curve and of course done with a slight convex shape. The reason I was considering using them (they are the dumbbell type) was only because the cam is not new either.
I don't know about the copper hardness, I know that when copper is worked, it changes hardness and should be annealed. I will have to do more research on that. The metal supplier says he has supplied lots of these sheets to vintage car guys. There is also a place in the States that makes them for you (out of copper if you want, or steel) but nearly $200 last time I checked.
