Need help with 383 setup

Well first off I'm running a kitted 727 with a 3000 RPM stall converter and a B+M rachet shifter. My best time so far is 13.8 sec in the 1/4 mile but thats with BF Goodrich banna skins leaving behind 10 feet of rubber. I'm getting 2 Mickey Thompson ET street radials which should knock of .4 seconds. Our altitude here in Calgary is 3500 feet and on a hot day I'm sure the engine would love to have a blower feeding it. I built the car mostly for show and it just goes like Hell and with the cam and intake it's just barely streetable. A buddy down the street has a 70 Duster with a 440 that's probably pushing 600 HP (no bottle) and he's in the low 12's easy.