I was checking outt Edelbrocks web site and was looking at their E-tec heads. There are 2 versions: the 170 and 200.

Here is what they say about the 170:
The E-Tec 170 heads feature 170cc Vortec-shaped intake and 70cc exhaust ports. They flow 20% more on the exhaust side than the cast-iron Vortec heads and produce power up to 6000 rpm. The 64cc combustion chamber will result in approximately 9.4:1 compression when used with stock pistons in 350-inch engines. E-Tec 170 heads come with 1.94" intake and 1.55" exhaust valves. E.O number pending for 50-state street legal status.

And the 200:
Edelbrock E-Tec 200 heads have 200cc rectangular intake ports and 78cc exhaust ports. They outflow the "fast burn" aluminum heads by 10% on the intake and 17% on the exhaust, making power up to 6500 rpm. 64cc combustion chambers produce approximately 10.2:1 compression when used with flat-top pistons in 350-inch engines. E-Tec 200 heads come with 2.02" intake and 1.60" exhaust valves.


How would a set of these work on boat motors??

If you had fresh water cooling or boat in fresh water only then they would wrok great! If not then it would be a BIG waste of money since the aluminum would get eaten up rather quickly.

Vortecs work great and since these are based on the Vortec design they should make some nice numbers.