I am running those heads, home ported with 9:5 CR on a 440 with a solid Cam from Racer Brown with 254@.050 duration .554 Int .525 exh lift. 1.6 rockers on Int.. My challenger is@ 3800 lbs with me in it. With 4.30 gears and an 8" ATI converter I run 11.20s @ 119-121 mph. Think it may be a little quicker with 4.10s. This is through mufflers and ET street radials.