The intake manifold will most likely be junk at the very least even a lot of times not even from saltwater usage - those intakes had brass inserts in the water ports and that caused its own corrosions for the aluminum to be eaten away. Many times this caused water to leak into the lifter valley. Dissimilar metal corrosion.

IMO I would pass and look for something else

Well sounds like I should wait, I'm not in a rush as the boat will not hit water this year! I was thinking it was a good deal, but I have never been around salt water before and I know its not a good thing..

Guy had an offer for $5000 so he sold it today anyways.

Jesus .
I wonder if the buyer gave it a intake yank and good inspection.
5k still isnt bad for a roller cam hp500 with carb and headers if the insides are decent. Esp if it has the flywheel alt all that.
I wouldnt of even wanted to make a offer without a real close lookover.
Ask the guy in mass that had the kamma 502s that ended up being peanut port gen 4 454's

IF you are a freshwater guy, you would be amazed..

The decision has been made on your behalf!
That's sort of good, you don't have to stress over whether it's worthwhile. Good luck as the search starts again!

RR

Kyle I bought my boat two years ago, 98 hp500 carb 180 hours, I pulled the engine for complete rebuild because I wanted some piece of mind. The intake was pitted and unsalvagable. The block was sonic tested and the machine shop refused to rebuild. Cylinder walls were too thin,Heads were rebuildable because most of the salt water drains down, I bought a new block and only reused the crank and exterior dressing. If you buy, buy cheap and plan on a new block and about 7k of other parts and labor. Just my .02$

Also my new motor will have a salt away system

I have yet to see a brasslined hp500 intake. ive also researched it and couldn't find anyone who had one brass lined.

I've had a few engines with Brass lined intakes but never had a problem with them being eating away or leaking. I do always flush and trailed. One boat I owned (25 Checkmate mtr) I docked from spring till fall without flushing except when I pulled to clean bottom every 3or4 weeks and had no problem or corrosion in brass manifold either.I have come across rot through into lifter valleys on a few small blocks without brass crossovers.I can see the two different metals reacting in salt water but it just has not happened to me, yet. I have a holley tall deck efi manifold only that has brass insert that I bought used at a garage sale that has no corrosion either.I do believe it happens though.