340 & 360 Cylinder head CC specs

If you really want to KNOW, you measure EVERYTHING. It's not that hard. I got a 6x6 piece of clear 1/4" plexiglass from work (for free) and a 100 cc. Syringe (used) from my vet (free). I use windex (used for other stuff around the house, so...free) to measure piston dishes, valve reliefs, and cylinder heads.
If I really want to KNOW, and didn't have my stuff, I'd buy a cc'ing kit.