Ford intake manifolds don't fit on GM engines. Yes it could be a Ford or Holley carb but the intake is some aftermarket with an adaptor plate for the carb.
The front PCV valve is doing nothing as it isn't connected to anything. Since you have an aftermarket air cleaner you could plug off the
forward hole and install a breather cap to replace the oil fil cap. As indicated previously, the engine must be able to breathe or it will
throw oil out wherever it can.
It does sound as if you may have a worn engine causing excessive blow by.
Fred
