I have a 1995 355 Aft Cabin with 454 carburated Crusaders with 480 hours. In June we did a comression test and both motors were all over the place. We knew we would be having problems. The port motor began to run a little rough, was kind of hard to start and would die while docking at the worst times. I used spray and cleaned the carbs and air cleaner.eventually it wouldnt start but it would turn. I had a guy look and we tried to start it and he said the starter was dragging and then the starter wouldnt even turn. He thought a new starter would get it going. Then we pulled a plug and found a slight rust on it. Since then, I have been going around with different mechanics who all have different ideas on repower. Some say rebuild what I have, some say get long blocks and start over from there, some say change to a 5.7 Mag, some say 6.0 minimum. Prices are all over the place and really high from 18k to 40k depending on the option. Last night I was speaking with a mechanic who suggested a valve job might be all we really need. Is there a way I can determine that? Any options? I am going to the boat this weekend. I am anxious to get it going again quickly. There are a lot of bad mechanics out there. I am not a mechanic, but have a small amount of knowledge and ability.