I am swapping the 454 mag mpi out with the 500hp carb the 454 is fuel injected and the 500 is carbed. As far as the wiring goes is there gonna be problems with wireing the 500? And is there any thing else that is gonna cause me issues.

i'm pretty sure on your 98 the round plug that connects the engine to the harness that runs forward to the helm is the same as the hp500 , should just plug in and everything works
mercruiser makes it real simple that way.

OK I hope that's true any one else wanna put there two cents in. It would be greatly appreciative so when i take it to get installed they don't try and take me for some extra cash.

What are you doing with the 454? I may be interested in it.

I ham selling it on ebay as we speek 4750.00

I just completed a motor swap the opposite way. I pulled out mu 454 Mag carb motor from my 1989 Formula 242 and install a 454 Mag MPI from a 1998 Baja. The wiring plugged in, all the gauges and even the electric fuel pumped worked perfectly.

Hey Cliff, how has the conversion to MPI worked on your boat. I'm in the process of doing the same conversion ( carb. to MPI.) on a 34' twin engine boat.

I did the exact same in 2003...everything hooks right up