I have twin HP 500's in my 1998 32' Fountain Fever with 550 engine hours. The dealer says that the engine has never been opened. I want to replace the valve springs. What should I get? I'm looking for dependability/durability, not necessarily a performance boost. Also, while my Tech is at it, is there anything else I should tell him to look for?

At 550 hours, you should do at least complete top ends with new head gaskets, valve job, seals, springs and locks.
Comp 929 or Isky 8005SP are often used for valve springs.

Thanks for the info. Approximately how much will I be looking at to have a shop do both engines?

I’d do the whole top end...the engine is open for surgery; might as well replace everything. Otherwise when do you expect to open it up again another 300 hours. I’d be leary of having 800 hours on rockers, etc.

id replace springs, locks, gaskets, rockers, lifters, push rods, seals, valve job, etc.

good luck.

Your fine to do the Isky springs mentioned above.

Also as a previous high hour HP 500 owner my advice is as above, get the top end done.

Pardon my ignorance, but why replace rocker arms and lifters? I didn't think they were regular maintenance parts.