Pressurized crank case?

Is this just a stock motor or what? What compression ratio? Is it a fresh rebuild with low miles? Headers? Exhaust system? There are so many variables here you haven't even touched on.

One thing you need to remember is if you have 440 cubic inches pumping on top of the piston you also have 440 cubic inches pumping below the piston.

If this is a low mileage fresh rebuild (probably stock type rebuild, no honeing plate) then you need to drive it for awhile to seat the rings. If it's an older engine you should start with a cylinder leakdown test.