Looking at the photos, I have decided that this engine is being built for some kind of spec racer, possibly a GT350.
The cylinder head is an early 289 head with narrow push rod holes and screw in stud holes, which makes me think it's an early Hi-Po head. The only reason I could see to use this head is if rules specify that you have to use appropriate heads for the model year.
The Molnar rod has to be 5.400" length because that's the only small block rod listed for the 302 on the Molnar website.
The weber manifold also makes me think that the engine is for spec racing.
The piston has the wrist pin hole close to the top of the piston, but does not pass through the
oil ring land as it would with a 331 or 347 engine. I've determined that,because of this, the stroke will be stock.
Therefore, my guess is the engine will be a 289 cu in and the horsepower, without knowing cam type or specs, would be around 375 hp.