This has come up before, and I kinda took a poll on racers running timing on B and RB engines.
I don't remember anybody running less than 34 degrees total, with most running 36-38. This is with verified time marks. I also informally did this at the track, talking to Mopar racers with the same results.
If yours is running great at 28 degrees, that just doesn't sound right, in a couple of different ways.
I've been running 38 degrees for years, on a street 440, and a race 500 ci.
