I cleaned the chambers further and unshrouded the valves. Will measure tomorrow whats the current cc. If my measurments are correct it will work no problem.
I built 446ci big block this year which was 11.3:1 with 244@050 solid flat tappet cam and RPM heads. It ran on standard gas just fine when the temperature stayed belowe 180 degrees. Finally we ended up putting different tstat in it and now it runs perfect on premium gas with 32 degrees advance and distributor curved to all in at 2200rpm. This is in a 56 dodge truck with 3.23 rear end with 3500 stall converter in 727.