390 w/open chamber heads

IF you only want 325 horses the performer manifold will be fine.

First thing to do is to take your cylinder heads to a machine shop,

bring your wallet because your heads will probably going to need surface grinding, new valve guides pressed in, spring pads will probably need to be machined. new valve seats, new valves, guide seals, retainers and collets.

For your power goals it's not necessary to port the heads whatsoever.

2.02"/1.6" valves will fit, anything larger would be unnecessary and may require notching of the bore (can't confirm this).

If you are going to CC your cylinder heads, do it after it is completely assembled as you will run it. Bigger valves make a smaller combustion chamber and vice versa.

Regarding cam selection, I strongly recommend building the motor around your camshaft, not the other way around.

The Lunati 60403 is a popular grind. It's seemingly a benchmark by which other street/strip hydraulic flat tappet camshafts are compared. It would create great torque in a 318 stroker but still give a hint of that hot-cam idle sound.

There are some youtube videos of this camshaft that will give you an idea.

A cast crankshaft is probably better suited to your requirements, just make sure it's not made by a brand name that Starts with E and rhymes with "legal" and "regal". :D