We replaced our tanks 3 years ago. We have a single engine which came out so we could get the old tanks out and the new tanks in. Our tanks are not square boxes so the fabrication costs were high. If you took out the engine rebuild and focused just on the tank replacement, we probably could have done the project for $20-$25K. Here’s the thread for project.
http://www.trawlerforum.com/forums/s...ent-28204.html