Offshoreonly.com - What to do 5.7L 260 HP or 5.7L 300HP????

Going to be doing a repower in my boat. My question is weather it's worth it to go from a 5.7L 260HP to a 5.7L 300HP.

Both engines will be carborated. They are mounted to an Alpha drive so really 300-325HP is the max HP that outdrive can handle. It is not an option to change drives.

The price difference for a complete engine is about $4,000. I'm thinking for $4,000 I could do a lot of other nice things to the boat (make the engine look all chrome and nice, etc).

I am really only concerned with Top Speed. The boat is a 21' Scarab I. The weight of the boat is 3150. Basically it comes down to $1000 per 10 HP which is a decent ratio in $$$ to HP.

But what kind of difference am I going to be talking top end? Is it the difference between 60 and 62 or 60 and 65? I'm willing to pay the extra for a 4+ MPHincrease but below that it's not worth it to me.

Comments? Best Guesses.