heads for 340

Ah, HA! Exactly! Doing your own work can be a huge advantage in head work, or anything really. Since Stroker can get a set of heads right, sending them out for a porting becomes a good option for a budget head set.

If doing such work in your area cost $500, then that is a $500 savings that could be rolled over into a porting job.

While the OE casting are harder to port out to a level of after market heads, even doing so may not be the best way considering the new heads more than likely have a better port to port as cast than the older heads. As cast port shape has a lot to do with it. Older heads may not have the abilty to flow as well as a newer head ported or not. And if so, the amount of work and/or port shape/volume may not be in your best interest.

Again, a lot depends on the build, target of performance and cost.

If you can get a older head to the level you want without spending a mint on them, go for it.
Your heads can do what is needed. Cost is the barrier. (Or want.)