Re: after market products
Just remember that this is a boat and not a car. Whatever cam you chose needs to be for "marine use"; ie power made under 5000RPM, minimal overlap to prevent reversion etc...
You probably already have to re-gear or replace the upper unit(should be 1.5:1) due to the increase in power of the 350. Was your 305 a 2bbl or a 4bbl?
As mentioned above, exhaust manifolds for bothe engines are the same. They come in to basic designs, rear dump and center rise. The latter flows better, and you can get partialy tuned (Dennis Moore designed) manifolds from GLM. They can net a few hp and would not be worth it as an upgrade, BUT since you have to replace yours anyway (per your other thread) then these manifolds make sense as the cost difference is minimal, sometimes less.
Bottom line - your 350 with a 4bbl will be good for 250-270hp depending on cam and intake manifold. Which is a good boost from what the 305 put out, especially if it was a 2bbl.
For more fun, you could build your new engine using vortec heads and produce power in the neighborhood of 300hp.
However, your are still puting this power infront of a 25 year old drive and into an equally old hull that may or may not be able to take avantage of or even handle. Perhaps you could post some pictures.
Whatever you do, keeps us in the loop.
Good luck.
