headers or manifolds stock 502
 

who makes the best, ie. the most horsepower for the money? There are so many options out there it is hard to chose from all and make a dissision. i am also planning on making some minor mods next winter also.

In the most horsepower for the money and pretty good looks to I would vote Dana Marine as tops!

Regards,
Ray @ Raylar

There are some great products out, Dana is one of them. Keep in mind you may have to relocate a few things and this will add costs. If you shoot me a pm or post some pics of your application I can help you get it spec'd out.

Before you all go making suggestions on exhaust manifolds, it is important to know what C.I. displacement the motor has? I know that he wrote "stock 502", but he went on to write "some mods" too. Does that include increasing the displacement?

I had Danas on my stock 502mpi and I liked them. sounded good and was the most bang for the buck. It was on my lod boat 272 baja.

The DMP manifolds have larger primaries and more flow ability than 1 7/8" tube headers. Our risers are available in 3 different inside diameters to accommodate a very wide range of HP.

What is the runner length?

I think you're heading in the right direction, but it will depend on the mods you're doing to your engine. What kind/cubes, HP rating of engine is your engine? If it is a stock Merc engine, then you will see very little if any of a gain at WOT by just bolting on a set of aftermarket exhausts, however you may notice more a nice kick in the midrange excelleration.

You're doing the right thing by adding a well breathing exhaust system FIRST! Depending on the upgrades/mods you do, then the more a better breathing exhaust system is going to work for your engine to give you more speed at WOT or peak/upper RPM ranges.

Much of it depends on your engine's cubic inches and the application....I would think a good quality aftermarket manifold type exhaust system like a Dana Marine exhaust, Stainless Marine or something comparable to those would be suitable for your engine. Besides the big weight savings, they will dress up your engines nicely as well.

Somebody correct me if I am wrong, but I highly doubt the high dollar tubular header type of exhaust systems will out perform a manifold system unless you're entering at 540 or larger cubic inches.

Hope this has helped. Have fun.

The DMP manifolds with our Vortex riser make a 27" long runner. Almost twice the length of a traditional 1 7/8" tube header. (15 1/2")

The Eickert cast header has a 32" runner length. Are we to believe that this was specifically designed by Keith for a 502 C.I. motor?
http://www.keitheickert.com/detail.aspx?ID=7773