Hughes engines has camshafts designed just for Mopars that take into consideration the large .904 lifter. They claim that because of the large size of the lifter they can get aggressive with the ramp and create "roller" power with a flat tappet cam. Check them out and see what you think. I have spoke with several people who swear by them. I personally have not used them though. They are a bit on the pricey side and you MUST use their springs or they won't warranty the cam.
www.hughesengines.com
Tim