looking for some help on a 340 build

Brain is so right. Getting that HP level isn't exactly OOTB stuff thrown on a engine. Porting the iron heads would be cheaper in away over getting Edelbrock heads OOTB and then off to the machinest for a check out.

Stroking the engine is great for torque production! But, that's a bit of coin to spend and all you have is a bottom emd with stock parts up top or just a lack of parts.

Building a 340 up should start with a excellent short block. Once you have that done, then turn to your heads where the rest of the budget will get eaten up. The heads being the problem in this... so far... is that stock heads need a good bit of port work. Paying for it can be costly.

Consider your going to start with a bare head and besides clean up and magna fluxing for cracks, your looking at all new parts there after and then porting labor. While, IMO, it is probably worth it to port the OE heads over a Edelbrock head purchase and then machinest check and correction (If need be) the ceiling level and overall flow curve of the OE iron head may not be as nice as it should be.
Even so, if it can be, it may not be as nice to drive as it could have been. OE heads are cpable of this power output.

Brain has some nice Indy heads he works on that have very favorable flow numbers. Bennifits are the heads are new through out and are worked on by Brian who has experiance in this feild. The Indy heas are reasonably priced to start with. And still so after Brian works on them.

(Discloser; I normaly don't provide such (raving like) reviews of members here and there work.)