I'm using an Integrated Engineering (IE) surge tank which looks to be what a lot of the eBay sellers have knocked off. It has a beefy 1/2" bulkhead and submerges and seals a single or double 044 pump with an oring. I have mine mounted on it's side and still works well. It also uses ORB fittings so no wories about getting thread tape inside the tank. I believe someone did a write up on rx7club installing an IE surge where you're suggesting.