I replaced my steel tanks with aluminum a while ago. I was able to slide them out the engine hatch by myself. Had to cut @ inch out of the stringer. I have tank diagrams and more detail if you want to email me
mhoman7078@aol.com. The quote was to fabricate 2 3/16 alum tanks as per email with all fittings and new senders, shipping included $2780.00 s/s tanks $3760.00. I ended up picking them up and bringing them on a boat trailer in 2007 from NJ mailto:info@custommarinefueltanks.com Custom Marine most likely will still have the specs but I still have a paper copy of my drawings. You do have to move the genset and to the side and remove the 2x4 support behind the engine to get the tanks out without having to cut them. I used boards and blocks and a come-a-long to pull the tanks out and slid them up the engine hatch. Maybe I should have cut them up but I didn't. You should put rubber strips under the new tanks and bolt them down. I put new hoses and fill hardware. If you have the yard do it plan on 10k.