Need help on a friend's 93 Pantera 2.He Blew his motor up at Gunnersville. He swapped a 175 mariner for a 95 200 mariner with rebuilt powel head with 175. Boat would run 60 GPS with 200, it would run 53.3 with a 23 pitch, tempest plus at 5800 RPM. Then tried a 26 pitch tempest plus at 5500 RPM would run 55. Then we tried my prop off my 93 classic on my boat with a 175 mariner at 5600 RPM, it will run 67 fully loaded. Then we tried it on his boat at 5600 RPM it will only run 60 GPS. Called the mechanic he got his motor from, he says he has had 2 panteras and sixty is all it will run. He called Basscat they said it is a 70 to 72 mph boat with a 200 motor set the prop shaft at 3 and half inches below pad went up and down with no change. Any help will be appreciated.