Your father has been into some serious stuff. Old Hemi's and new engines may be a bit different in execution, but physics doesn't change. He still knows how to get air into a blower, out the ports, and get the most out of it in between.

I'm looking forward to what you find. My car fund is ear marked the new parts I'm dropping in the hot rod but it sure is tempting to mess with the SRT.
How many miles do you have on your SRT? It may take 3,500 or 4,000 to loosen up. They've got a long break in cycle that is held in check by the engine controller. Once it lets go, you'll be able to run a little better.