Re: any questions
So it will be a 221 with 250 2v head
Have u ever considered efi?
i think a 350 holley would be fine consided it was setup for ur application, i mean down jetted and decrease power valves also maybe backing of the full throttle mark to only 3/4. This should be fine for a 250 but with the 221 might flood out unless ur revs are up cause the 250 head will lower vacuum mean lower airspeed in the ports so it will not flow too well at idle but u could tune this out with a holley even dual sidedraft webbers might be dooable.
Maybe even advancing ur cam to increase vacuum might help but like u said she will be thirsty so i would suggest efi anyday