What size engine for the online/Youtube EC?

Just a few small things that may need to be clarified.

Cylinder head porting.
It may be worth while to clarify whether material can be added to the ports/combustion chambers.

If I understand correctly the spirit of this competition would likely prohibit welding/tubing/putty etc to raise the port floor or minimize the pinch. (However if people are willing to do that I personally would be very interested)

Intake manifold.
A single carb flange of 4150 is specified, but It isn't specified whether the intake manifold needs to be based on a mass produced item.
(Once again, It is unlikely that anyone would enter with a fabricated intake manifold, but if someone is willing to do that I am personally interested to see the results)

Oil control
If I'm understanding this correctly, something needs to specify that dry sump systems are prohibited as this is cost prohibitive to the average person and not on the spirit of a budget build.