Thanks for the information Eddie. If you had to guesstimate off the top of your head, what do you think the cost of something like would run??

Having never done it, I really would be hesitant to even offer a guess. Maybe someone that has done it can chime in with a better answer. It appears as though Brian did a swap so he may be a much better choice than me to answer your question. Sorry I couldn't be more helpful.
Eddie

When I read Ilmor I thought he was talking Merc V-8 to Ilmor V-10 not a similar V-8 swap. The boat we did was GM 502 to Ilmor 625 V-10 with a Arneson conversion which required the stringers, wiring, fuel system, custom engine mounts, drive height and exhaust hole location changed......other than that it was plug and play.

Yeah. And then if you do the swap, you're gonna need a drive change more than likely as well. Those bravo1's will never hold up...

To 430hp???