I have a 1990 Yamaha WR500 that I am replacing the manifold on. The old one was rotted out. I have the old one off, and the new (used) one ready to go on, but I was wondering if I should dress the new manifold gaskets with anything (hylomar, loctite 518). I know this is a point of some contention with manifolds and risers on I/O powered boats, I wasn't sure if there were any tricks with my old waverunner. The mating surfaces will probably have some pitting, so I was thinking of coating the new (OE) gaskets with permatex hylomar.