I have a 1998 SPL 90 hp Johnson, Ser# G04471967 (V4, 90 degree, cross-scavenged)with a blown main bearing, requiring a new/rebuilt powerhead.<br /><br />Can I replace it with a 115 hp powerhead? My boat is rated for a 120 hp and I'd like to get the extra HP in the process. What, if anything will...