Been discussing this with a friend and he seems to think that you can get more performance out of the logs than a set of headers. His understanding is that the logs have more back pressure, my understanding is that headers help in more horse power. This is on a 454 chevy engine that has a mild cam, its in my 79 sleekcraft rebel. I like the headers cause they look badass but are noisy as hell and I guess cause of the noise and looks they seem to make more power, its in the mind I know................

I might put the logs on tomorrow and see if the boat has the same top speed as when using the headers, maybe that will tell me something.

Header will always I flow a lot better then the logs.  But need or HP will depend on your set up.  It's a lot like having ten foot of two inch pipe attached to two feet of 1/2 pipe not good for flow.  For full HP gains all of your components needs to work together.  However I had a mild 450 HP BBC that ran better with baffles in.  Some set ups need a little back pressure but logs will never preform better then headers.

Although this is a year ago I'm thinking I'd like to hear more discussion on headers vs logs anyone else have experiences with all this?

9 times out of 10, headers will give you better performance. A buddy of mine went from normal logs to headers and gained 400 rpm and 5 MPH. stock 454 and a heavy ass southwind 20 

I can only hit 4 k w a 455 c heads .030 over 280 comp cam and I have logs n over the transom.  I hope to pick up a few rpms.....

What impeller   my 9.5:1 455 with stock Ka heads turned an A  to 4800  with logs an small 2.5 inch snails

a impeller I think my tach took a poop goin out this weekend w new gauges lol we shall see.....