cyl pressure to high?cam to small?

i have a 468 . im running manly 50 cc dome pistons with 990 heads. my cam is a solid flat 258/268 at .050 lift 595 621 intake installed on a 105 i have noticed that my starter was working very hard so i reworked the distributor so it had less initial advance and it starts good . i did a cold compression test and its between 215 and 220 . thats cranking until it stops rising. with the throttle open. is this to much? that has to be 240 hot. im just thinking i should have added more cam. i can say one thing it is responsive .thanks