Since your rebuild only has about 1400 miles on it I would be taking the heads back to whoever did them for you and demand they fix them. (Unless you did them yourself in which case you have no one to blame but you anyway). Freshly rebuilt heads shouldn't have faulty valve seals.
You do need to run the PVC system. You have to have some way of evacuating blow-by gasses from the crankcase and a PVC system beats the old breather tube hands down. It's more environmentally friendly as well.
I think I would temporarily install a mechanical fuel pump, disconnect the electric one and see if it makes a difference. If so then your problem is definitely the electrical pump.