Cam-shaft

There is always a lot of opinions on this subject. However, your best bet is going to be CMI's. You can get exhaust from them that will work for you application and in the long run you will be better off than an alluminum manifold. If you are running in salt you are actually better with a painted cast iron manifold as far as longevity. CMI's will give you the chance to grow with your motor if you ever decide that as an option. If you decide to go with manifold to a riser style exhaust make sure your transfer from your water ports are completly a seperate part of the exhaust not just a riser gasket. That way when they start leaking it will not go into your exhaust ports.
Thanks, Cam-shaft.

awsomethunder

thanks for all the input,i like the looks of those danas.it seems like no manifold is going to make me more power in itself.since i want to supercharge next year i think i should go with cmi.are cmi bolt on and go.i went to the web site and seems like they want alot of measurements.i really don't want to modify anything.

dana marine products

dbkski - I spoke with Water and Wheels a few days ago. FYI, I have located a stock Merc late model bracket such as the one on your engine. We have made the necessary modifications, re-powdercoated the bracket, and it's on the way to Water and Wheels. He'll have it tomorrow. Sorry about the delay. I simply have never run into that clearance issue before.

ThruHull

What engine are you running?

Ateco

There are several options in the CMI line that will probably not break the bank. Each has their own purpose depending on your application.

There is a reason they are the number 1 selling header on market and that's why Mercury Racing and Ilmor use them exclusively.

Give us a call if we can help or provide more information.

Don't settle for anything but the best!

(847)623-2737

awsomethunder

97 454 mag carb

ThruHull

I wouldn't mine going the CMI route but I am running EFI and don't want to go through the trouble I have read about on here with reprogramming.

Rage

When a stainless steel header fails what are the potential causes in order of probability of occurance?

Cam-shaft

If you do not want to deal with re-programing then you should not look at anything other than a stock manifold. A good exhaust is going to need to be tuned for sure, that means you are probably going to make more power because you are pulling the fuel and air out quicker. Just an idea.
Thanks, Cam-shaft.

ThruHull

I need to replace my stock manifolds now and I was trying to get something that would work with a repower in the future so I don't have to do this twice. I am getting alot of different opinions on whether the ECM would have to be redone or not. I am running a 7.4 MPI, so I am not looking for any performance gains really and don't want to raise the Rev limiter due to the weak internals. Just trying to get something that will work now but will also swap over to a 540 in the next year or two.