I would build an High Output 305 and use Hasting piston rings.They will seal well @.019 tapered bore as long as your ring lands are clean and free.An HO 305 was a good runner.

Wanted Good Woman:
Must be able to cook , clean , sew , tune engines and polish trucks. Must have old Stovebolt and garage. Please send picture of old Stovebolt and garage.