To everyone that gave suggestions in this thread, thanks! It was the cat. I bought a new one with 2.5" DP from ZZP. Little louder and faster (than stock). Most importantly, it gets out of its own way now! On to my suspension fixes...
good deal!!!
Black 98 Regal GS: best run 13.95@99.75
99 Red GP L36: 15.5 in 1/4