Another 75hp please

Hi folks,

My '72 Duster has a 1992 MP 360/300hp Commando (pre-Magnum series for you younger members) crate engine; B/G 625 cfm RD carb, TTI long tubes and K&N filter. It's a 4spd 833 with 3.23 8.75" rear.

I like the car and as it is a street car (NOT a DD though) it's pretty much fast enough. How fast? Well, certainly not real fast and not fast enough to impress anyone here I would think - and I am not trying to; just want to inform is all. The best way to put it that it can just barely edge out a stock Magnum R/T if I launch it right (problem there being that it's a 4spd car with 60 series street radials - old tires / hard rubber at that ... just receive new tires waiting to get mounted).

I would like to put another 50 - 100 hp into the engine w/o opening it up and would like most of that power (not all, just most) in the 3-6 thousand rpm range.

I was looking at the edlebrock RPM perfarmance package for Mopars:

http://www.edelbrock.com/automotive_new/mc/power_package/rpm_power_packages.shtml

What does anyone here think about this option? Any other ideas that sound better?

Right now I run 93 octain with 34 total adv. Probably could get away with 91, maybe even 89, but I drive it so little that the extra few bucks arn't really an issue. But I do NOT want to go over 93 under any circumstances.

Also, the car get 16 mpg at steady 65 and I'd like to keep most of that.

Thanks and best regards,

PS: I am not going to change either the tranny or rear gears - these are not options.