There are basically 2 heads for these engines, the later style 230,250 and 292 head which had anywhere from 74-76cc's in uncut condition. The early 194 head was in the 64-66cc range. The deck height on most of the 230's and 250's was around .020" to .025", but you should have checked it when you tore it down to get a baseline. The 230 had flat top pistons and the 250 has dished, so swapping cranks wont change your compression for a stock rebuild in a 250 unless you buy custom flat top pistons. To get the most bang for your buck, put 1.94" and 1.600" valves in the large chamber head and put in the bolt-in lumps in the intake ports. If you find a 194 head, you can use it as an extra anchor
. A group of us on Inliners did many dyno tests with both a 250 and 292 engine a few years ago, over 200 dyno pulls combined, and found that the 194 head never made as much power as an equally prepped big chamber head, it actually consistently made over 10 HP less or more on every combo we used them on.