I have to pull the starboard engine to replace the sea pump, while it is out i can get to the port side and replace that pump as well, at that time I was thinking about big tube headers what do you guy's think worth the $$$ or not . And while i can get to everything any other parts I need to look at replacing
Boat is a 29 w/twin 350 mags

Headers don't help that much on small blocks unless you are going to build them up a bit.
I would just buy some good free flowing manifolds and riser ells.
Rebuild both seawater pumps.
There are a lot of things that you can do to small blocks to creat lots of HP. ( heads, cam, intake, carb )
real easy to get to 450 HP.

FYI -- on Big Motors.

http://www.keith-eickert.com/exh_specs.htm

I personally prefer the CMI Tube tops over the KE's due to the low and midrange punch they have. The KE's only look to come-on at 4k RPM's.

Mine has Stainless Marine manifolds and risers on it. They were good for 1 mph over stock manifolds. It was a GPS comparison from one day to the next. they were installed without removing motors.

Hey guy's did it help the sound it has stock manifolds and it sounds ok,, I was hoping for a better deeper sound did that stainless marine help in that department?

Yes the stainless marine manifolds helped give it a much deeper sound.

Brian

so do bigger motors! haha.

I have the Eickert headers on my 29 with a single 500 and it sounds really nice. They perform really well too.