Couple of updates.
Finally finished my header fab. Still have to finish weld all the seams and make cutouts for connection to my exhaust but I am relieved to have the bulk of the fabrication behind me.
Also got a picture from my engine builder. He mocked up the pistons to measure piston to deck clearance and chamber volume.
Specs are as follows
70cc chamber
-.003" piston to deck height.
Compression ratio is ~10.9:1 (less than I wanted due to gigantic valve relief)
Quench distance is going to be .043-.045 with a .040-.042 compressed felpro head gasket.