with a cam that big, you better just put in a high stall torque converter. ( electric lock up ) I had a .454 lift 272 duration in the wife's dodge, ( 318 ) and the dam trans just hated it. ( 904 ) I put in a mild ( first step up from stock ) stall converter, and it was only negligably better. So, I put in the next higher stall converter available, and it was noticably better. If I were to do it again, I would definitely go with an even higher stall.

Also have a .454 lift w/ 290 dur in the firebird ( 305 ) with a 350 TH and I believe I put in a Summit converter, mid range stall. Does fine.