Dyno #s ??

Took my 388 ci Dart for a few dyno pulls last Friday.The shop has an inertia type dyno Mustang brand and are supposed to be real accurate.
It made peak SAE #s 292 lb-ft torque and 328hp at the rear wheels - and I know we do not race dynos, but was wondering if there is a conversion that would relate these numbers to other types of dyno numbers - the guy was talking about a 15% coversion for equivalent to ??? and then 20-25% for flywheel. All I know is I was very pleased with the results and for $150 well spent.
The real benefit for me without a bunch of track time was dropping the timing back 4* to 32* and gaining 10rwhp which then made a slightly lean condition so we bumped the jets a couple of sizes and picked up 2 more and a final fairly flat air/fuel of ± 13.3
If I can figure out how to post the video I'll share - man does it sound sweet from 3000-6500rpm