Help -- Eshaust manifolds and risers for 5.7L Merc
 

My 5.7L Mercruiser sterndrive has seen seven seasons and 350 hours, all in the
Chesapeake Bay. About 3 years ago I removed the exhaust manifolds and risers,
had them burned and magna-fluxed (no problems) and returned them to service. I'm
thinking that I may need to be pre-emptive here. The end of this season may be a
good time to replace them.

Questions. Are any brands better than others in terms of holding up to salt
water? Some are advertized as 'ceramic lined'. Is this a big advantage? Are
stainless steel manifolds and risers worth the increased cost? Where would be a
good place to order parts from?

Thanks for any help you can provide. I remain, respectfully,

John
On the 'Poco Loco' out of Deale, MD