Just joined. Retired 8 months ago. Need some help on a 455 hardin olds. Have a Rochester on a 290 HP now. Don't know the spefic type as the boat is 250 miles away right now. Does anybody think I would be smart to go to a Holley for 325 or 345 HP. That should get some responce. By the way, the boat is a 18' Marktwain. Any thoughts. Gota go.