Hi,
Reading through all of the threads, while all make good points, I'll offer this:
A couple of things come to mind.
1. What's with the "hard launches"and when did you start with this?
2. Having a good working PCV system on any of our engines is a must, for this reason(s).
a. They reduce crankcase pressures, which inturn reduce tendencies for annoying oil seepage. I would even go so far as to recommend a "closed" system, as they do a better job at reducing these pressures. There is an added benefit, of parasetic HP gains through less piston resistence. Also, not to mention, helping our environment
3. Did the "shop" install low pressure rings? Ask about this.
4. I think you mentioned this is a 347. If so, there are two versions: Long rod and short road.
The "long rod", when running an 8.20 block, places the oil control ring partially within the wrist pin openings and while this may be fine for racing, IMHO, not fine for a street warrior whose owner is looking for longevity in his engine. The "short rod " version, leaves just enough distance to allow that oil control ring to be "wholly" within the piston circumference.
I learned these things when researching and designing my build and is why I chose a 333 (.040 - 331 stroker) for my street warrior. I get plenty of "grunt" with it making 392 RWHP @ 6100 with 400 RWTQ @ 4400 Rs. It does have "low" pressure rings, which only expose their nastier qualities during the dyno runs. But none of thse runs took place until 1500-2000 miles were logged.
So, ask the shop about the last 3 points and keep you "foot out of it" for a little while longer. BTW, ask them if they installed umbrellas or posi-seals?
Happy Motoring!