Vacuum advance

To Dartfreak 75.

The only difference between PVA & MVA is that MVA is operating at idle, PVA is not.
I suspect your engine will benefit from MVA. Easy to tell. Hook it up! If idle rpm increases & idle is smoother, then the engine likes it. It may not want all of the available advance that the VA can can deliver, so a stop would need to be fabricated to limit the total VA.
The difference between a locked dist providing, say, 34* at idle & MVA giving 34* is that the engine is always going to see 34* with a locked dist, which might produce pinging. MVA is load sensitive, so the 34* will reduce to a lower number under load.

You would be surprised how much extra idling timing even stock engines like.
Example: Pontiacs idled with 26*, 6* init + 20* MVA. These were high comp engines [ 10.75 ] with mild cams. Lower CR, more cam duration, needs more idle/cruise timing.
What is different between a Pontiac & a Mopar? They are made of cast iron & ingest fuel & air.