baronbob

I have a 7.4 mpi with a procharger M1. I would like to up grade my stock headers to a medium priced header that will fit my stock set up that I have plumbed to a crosover through hull exhaust. In other words, I need to be as close as possible to the stock Merc location of the riser output.

Griff

If the transom exhaust holes are in the stock location, then any standard performance exhaust will have the riser exits in the same location.

Kidnova

Revolution Marine is a pretty good bang for the buck. I think right around $1,000.00 for black. Few hundred more for polished aluminum.

I went from stock Mercs to Revolutions. Got noticeably improved mid range but not much more on top end.

tcelano

I have had excellent results so far with my Revolution Marine manifolds. I have heard some people complain about corrosion problems. I run in brackish water mostly, and flush religiously within usually 20 minutes of haulout.

The only gripe I have had with them concerns the fact that they did not plug the threaded holes during the powdercoating process. Nothing like only getting a fitting in one turn before it locks up. A $30.00-$90.00 1" pipe tap, depending on whether you like the Chinese or not, solves the problem, but it should be easier to fix in production. Purchasing the polished set would totally avoid that problem. Your $1K gets you manifolds and risers, but no 1" water hoses, tail pipes or couplings. I made my own using 4" Stainless tubing, and welded in some mufflers from Hardin, and high-temp silicone couplings. Going this route, it's all said and done for inside of $1200 per engine. Any decent header package will run you $2500 or more, with tailpipes probably extra.