The time has come... 440 freshen for B-body

i'd keep the polara together, get a 440 or 400 from a salvage yard and go after that instead

get it all built up and plunk it in.

i'd also see if a local machine shop will help you learn / help you port the heads. that way you avoid some mistakes plus they can help you clearance everything with your new short block. most shops are pretty cool i'm sure you could find one that would teach you how to port a set of heads. maybe even help you with the valve job too.

they love to teach people.