Nykamp, I'm telling you, the downtubes are the way to go. I have staggered #6's with 1000hps, and they work great, no back pressure once on plane. The center exhaust pipes only have 3/4" between them and the clamp-on's fit. They're quiet as hell at idle. I'm not near the boat now, but i will be this weekend, i'll take a picture.

Steve's stagger will provide a little bit of a challenge for down spouts. The starboard, inboard pipe, comes out right over the port transom housing.

What an ODD configuration!

Gary,
What is the drop from muffler centerline to the end of the down pipe on the ones you have for sale? I may be interested in those for my Cougar, or modifying my Gaffrigs in a similar manner.

Jim

The dimension from the center of the muffler to the tip of the "down-tube" is 18"
Do you need any other dimensions?

I just looked @ the transom on your Apache.
I believe it would be possible to take the 2 port pipes and "drop" the "down-tubes" to the left of the port drive and take the 2 stbd. pipes and "drop" them to the right of the stbd. drive.
The ex. pipe between the drives would probably have to have the horizontal run of the "down-tube" lengthened a few inches to clear the gimble.
It can be done.
Give me a call and we could discuss it.

Gary Kollofski
ph: 763-473-8963

lol, yea who built that thing anyhow?

What type of switchables do you have on there now? Did they test with them in the "silent" position? Also, before you spend a bunch, it looks like the law will change, within the next two years max, to where we will also be tested at speed in Michigan (similar to Wisconsin's law), not just at idle.

I am going with the new CMI's 5 by 6's from Fred @ Trick, Thanks Fred. Steve

What are "new CMI's 5 by 6's"? Why did you decide on them? I'm looking for mufflers for Mercury HP525SC motors. Appreciate your thoughts.