Re: Intake Manifold options
I changed to a Holley aluminum intake the year after I got it new. It saves 50 lbs, flows better.
To protect it from the salt water, I'd clean the water passages with acid, then detergent, then a demineralized water rinse, let dry. Then seal all the water passages off but the thermostat, pour a pint of GE Glyptal paint into it, seal the t/s hole, tilt the manifold every direction to spread the glyptal. Remove the plugs/seals, drain the excess paint, let it cure in the sun.
Glyptal is often used by racers on inner engine surfaces to help oil flow easily by smoothing the rough sand cast surface.
If Glyptal is not readily available in your area, 2 part epoxy paint will work also.