magnum casting numbers and engine quest question

Stage II is only a valve spring upgrade, not ported. We dont recommend porting EQ's unless you are going for at least 500 HP. We also dont put 2.02's in intake as I think you loose power over a 1.97. We dont tough the exhaust. We do have them gasket matched or bowl hog on intake only, but thats it. The OOTB heads will make 450+HP without touching them. I see guys put 2.02's in them and dyno at 450 but you never see them dyno with 1.92 or 1.97....ever wonder why?