Thanks guys....just need to be sure that I can run my boat the way I run it with headers. No need for premuim to combat knock, and real HP gains..enough to warrent a bigger prob.

Tubular headers will allow the exhaust to exit more easily than a stock set of Merc manifolds, and yes there are some headers that provide better scavenging than others. Until now that was the only way to go because manifolds could not quite compare with rare exception.. Just having open flow exhaust on a stock or relativley stock engine is not always going to allow it to perform better. Part of the reason for runners in headers & manifolds with runners is to tune the exhaust & try to create a scavenging effect.. Some headers do it well, some ok & some not at all. The design of the manifolds By DMP is designed to scavenge & it has individual long runners & a vortex (venturi) built into the riser to aid in the scavenging of the exhaust. This is what helps to quickly remove the exhaust & pull in more air fuel mix..

If memory serves me you guys also have or had some Keith Eikerts that had long runners in aluminum manifold that tried to accomplish similar things at one point for NON 496 applications.

Also not all exhaust systems require cowl modification..

WE have used Hardin / Lightning headers in the past & I dont have anything bad to say about them. As far as headers go they are a good bang for the buck for certain applications. WE have had good results with them on Blown Jet applications..

However I feel the flow torque is currently the best bang for the dollar if you have the space to run a wider manifold on a 496

Jamie / Lakeside

Lightning does offer a 496 silent choice style system. Although due to the extended length of the runners, a shorter diverter is required. That is why Lightning's silent choice system comes complete with its own unique style diverter which is shorter than your factory system.

Ultimately Dana makes a great manifold style system but if you are looking for MAXIMUM power gains a tubular style header is the way to go.

Lightning says about a 40 hp gain on the 496 and 50-60 hp gain on the 496HO. Unfortunately I do not have any dyno sheets to share with you guys at this time.

Maybe we should get a non-biased second party to do some dyno testing, I'll be happy to pay my part, that way we don't need to makes claims out of mid air. We'll have some results to show.

Tubular, square, etc... The thing about exhaust that builds power is the way the runners are tuned, the length of the runners & the way the collector is designed. It doesn't matter whether it is in a header or a manifold. The designe & flow is key..

We have used lighting, we are also a distributor for them. Not a bad product, but if corrosion is a concern then you must use the full stainless ones as the standard ones are ss inners & mild NON stainless steel outer pipes..

IMO.. If I was a consumer I would also ask myself what substantiates the best header, manifold etc.. Who & what substantiates the most power gains? A dyno or a simple it makes the power because the manufacturer says is does but doesnt back it with a dyno sheet?

Again Nothing against the other exhaust systems who's ever they may be. They all have their good points & bad. Headers do have their place as I said before, they can also rot, crack, etc.. Manifolds are not prone to cracking @ the flanges & they can hold up quite well to corrosion, or at least better than non stainless steel.. In the end one must go with the exhaust that will best suit thier needs overall..


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Great thought.

At CP Performance we are proud to distribute the industries finest 496 exhaust systems.

so for the lighting headers, you have to buy a whole new silent choice system.

This is great, now if we can get someone (maybe Raylar if he would do it?????) to step up with a dyno and a 496 (hopefully HO) "mule" to do the testing. I wonder if there would be anyone else with "boys" enough to "step up"?

There are advantages to all the different kinds of manifolds. Price, style(looks), options (like silent choice compatibility), size, color....... If we had raw facts on performance we could make a better informed decision on what is best for our application. Bang for the buck is different for all of us. I don't think the all out leader in HP and TQ will get all the sales, I really think there is a lot more to it than that.

I wonder if CMI, Hardin, Stellings, or Eddie Marine, (others???) would like to get in with their headers/manifolds?

CP you threw out a price for the black and silver coated headers how about the stainless steel headers, I thought they were close to the same money as CMI....just curious

IMO if you are going to spend 4500-5500 on exhaust that only get you 60 HP max I would purchase a procharger or annie up a few more thousand and slap on a Whipple or Raylar Kit and get real HP gains....again just my opinion, then again I am one of the few to purchase a 6500 MYCO trailer for my little Donzi 22 classic so forget what I just said.

Undertaker