My 28 daytona has started taking longer and longer to get engaged into forward gear. I have accidently dropped it into gear at 900-1000 rpm twice. I am running a blown 509 making around 850 HP. drive has 1;32 gears. Drive was rebuilt around 50 hours ago according to previous owner, who knows how accurate that is. I have religiously changed the drive oil (amsoil severe gear) every other month thinking it was cheap insurance. My local boat guy says the drive is shot and he has a IMCO sc drive upper/lower for $5k and my XR as a core. Would I be better off fixing my XR or buying his SC drive.