I sold a friend a Mopar Purple Shaft 284 street hemi grind for a 383 motor going into a 1968 Charger with power brakes, he owned a automotive garage and it was for one of his bigger commercial customers Son car. I help him degree it, it had right at 4.5 inches of vacuum idling at 850 RPM in gear
That's strange... must have been something else wrong since you degreed it for him. Huge vacuum leak maybe? I put that exact same Purple Shaft cam (284/.484) in my basically stock 383 rebuild. It idled with a very minor lope at 13" vacuum at 750 rpm!
