Merv, For what it worth.
In a previous life I was going to build a 392 Windsor based on a 351 Windsor block and was looking at putting a mass-flo injection system on top of it.
In fact the mass-flo injection system was what enthused me to consult with Qld. Transport (God bless their souls) as to whether they would accept the engine given a whole heap of emission data forwarded to me from the mass-flo folks.
In fact, the objective was to try and get Qld. Transport to accept an injected engine along the above lines for Qld. Cobra club members. Don Pilling of Snakebite fame and myself started the process but eventually it all fell into a heap. The key was/is access to a testing station.
The advice was ... they would certainly accept the engine if we could prove the emission status. They (Qld Transport) even gave us the name of a company in Brisbane which was looking at setting up an emission testing station. Sadly, that company did not invest in the equipment, owing, in their words, to lack of some agreement with Qld Transport.
Long story short, The mountain of research I undertook for this engine lead to the following conclusions. With any small block windsor do not install high volume
oil pumps. There are a number of reasons I wont go into here but a blue printed standard pump is more than sufficient.
Secondly, AFR heads were the ducks nuts. The size (165/185/205's etc.) of the heads would depend on the cam chosen and the desired rev range.
I would suggest you consult with the mass-flo folks as to some past installs matched to your end desires.
What I can tell you is that a friend of mine did build a 331ci windsor with a mass-flo on top, AFR 185 heads, and a custom crane hyd roller cam. That engine went into a beautifully restored mustang and was an absolute beast.
It would start first crank, idled with a slight but purposeful lope, would behave in heavy traffic but would burn the treads in first and second in the heavy mustang. The transmission was a Ford Motor sport M7003A T5 with a 2.95 first.
I know this doesn't help much but I do think guidance from Mass-flo is the key to a balanced well performing engine if their intake is what you are after.