Hello , I need some help with selecting a set of new or used aftermarket or stock exhaust for a 2000 350 Mag MPI with silent choice. The budget is not very large and the boat is used in salt water. I was told that the stock mercruiser exhaust is not that great and could need to be replaced after one year of use. I just pulled the exhaust and the risers are not that bad a little fouled put the manifolds at the center exhaust ports are starting to leak. Any advice would be helpful. Thanks Jeff ([email protected])

I used to have a small block that I kept in salt water as well. I flushed the engine after every time I used the boat. I got rid of the original manifolds after 8 years of use. When I removed them , they still looked pretty good. No signs of leaks that I could see. I replaced them with a set of Imco PowerFlows. I saw no change in performance at all. At least they looked good..

Jeff, I would recommend a set of aftermarket aluminum manifolds and S.S. risers, like EMI's, as they will outlast the cast iron versions in salt water as long as you flush the engine after every use. We have seen as little as 1-2 mph gains and as much as a 6 mph gain with only the addition of exhaust. Down here in the salt water, cast iron manifolds and risers only last about three years. The problem is that when they start to leak you may not know that water is being reverted into the engine. Give us a call if we can help or for pricing.

I personally run the Stainless Marine manifolds. I love them but If I ran in Salt water I would run the Manifolds that Dennis Moore sells. I belive GLH is the brand or something close to that anyways. Stock looking but yet tuned runners....Same as the Stainless Marine just iron instead of alumunum...But a HELL OF A LOT CHEAPER!!!
I think Cuda has bought a set for his Donzi....

BH

Stainless Marine all the way.. I run damn near exclusively salt, no issues, no problems, no worries..

I may know of a set available: New manifolds, used Stainless risers if your interested..

Scott B

Yes, I bought the GLM's from Dennis Moore. I haven't tried them out yet, but they were a lot less money than Mercruisers, and are supposed to be tuned.

It would be real cool if the GLHs came in aluminum.......then Id be there.......doug

Thats GLMs...sorry. Revolution Marine is coming out with an aluminum smallblock header in the spring complete with risers ready to go for $899.......doug

Doug,
Dennis Moore's manifolds now come in both cast iron and aluminum. Check his website for pricing. If you're buying a couple of sets let me know, the price will be better if we could split the freight. I'd like to hear more from other members about performance gains on stock motors.

Even with freight from Cali to Fla, the cast iron ones were still more cost effective than stock ones here.