Also you must run some sort of crankcase evacuation system, PCV, pan evacs, vacuum pump.
You can order a new baseplate from BLP WITH the PCV port in it. Drilling a hole in the plenum won't do the PCV system any good.
More than likely there are cracks from porting. Have the heads pressure tested and see what you get.
Also, find a shop that uses a vacuum source to put a vaccuum on the intake ports. If it doesn't pull the full gauge you can bet it is cracked
