Re: how will these manifolds flow?
 

Hey, that looks like the manifold I am looking for to bolt onto my snowmobile!! :D

Re: how will these manifolds flow?
 

Cool 2 stroke v8's.....nice expansion chambers! :D :D

Re: how will these manifolds flow?
 

Classic log manifolds are low performance. There is a great article in Hot Boat this month on just this topic. They dyno compared log manifolds to headers, about a 50hp difference which is HUGE. This was on a 450ish hp engine so 10% change, 70hp with an arrestor change as well.

Re: how will these manifolds flow?
 

Only problem is can i use headers safely? The manifolds that came on the boat and the ones in the picture above have water cooled exhaust. How do I know if i can use headers? Are there any water cooled headers?

I'm new to the boating game so if the answers to these questions seem obvious, I appologize.

Re: how will these manifolds flow?
 

Definetly looks like Stainless Marine from years ago. A friend of mine has a 27 Magnum with 351 Fords and he has the same ones. Infact they are still running today. Fresh water boating.

Re: how will these manifolds flow?
 

so i figured out the answers to my own questions above, my last issue is $$$

am i going to find a decent set of headers (new or used) for under $1000?