Engine vacuum systems that use exhaust flow to generate a negative pressure at the crankcase are typically ineffective when the headers are run with mufflers and a full exhaust system in place; there’s just too much back pressure for a vacuum signal to be produced at the headers. A vacuum pump off of a diesel engine would be an easy option though and these are available in both belt driven and electric formats. But under normal driving and until the blower goes into boost mode, you do still have manfold vacuum present which means you can run a PCV valve.
With a 3.800” bore, 3.44” stroke, 78.6cc chambers with 471 heads milled 0.020” assuming they were 82cc’s to begin with, the pistons 0.010” in the bore, and a 10.1cc head gasket, the static compression ratio is in the neighborhood of 8.06:1. With this in mind and using a mild camshaft, 6psi boost and a conservative ignition timing curve will keep the engine alive on premium fuel. If the fuel mixture is leaned, too much total ignition timing is employed, the fuel octane is low, or just a small combination of each of these occurs, the engine will see damage regardless of the parts being used. A camshaft with a later intake closing event along with being ground on a narrower lobe centerline will give more latitude in the tuneup before experiencing engine damage. But modifying the camshaft specs so that the engine is less sensitive to the use of lower octane fuel will normally sacrifice lowend driveability and performance so the tradeoffs must be considered.