Drain tank and plug holes

I’ve got the car up on jacks as I pull out the exhaust system and fuel lines. I was originally planning to pull out the gas tank to use that space for 3 or 4 batteries but it looks like a bad idea. You need to pull the read subframe, differential and transmission to get the tank out! Plan B was to cut the sheetmetal from the interior and trunk area and pull the tank from above, but the tank is shaped like an inverted T and won’t come out from the top. I never liked the idea of having batteries in the passenger space anyway and there would need to be some tricky racks and tie downs for the batteries in that spot. I decided to leave the tank and put the 3 – 4 batteries under the hood by the firewall instead. I bought a siphon pump and drained the tank. I bought some rubber plumbing plugs at a hardware store and removed and plugged the vent and fuel inlet.