HP ratings, also the 044 isnt designed to be run in tank
BUT
There are so many people with 044 in tanks that have had zero issues, including 2 gtr's i know of which are thrashed properly, and mine. There will be a tiny bit of tinkering to get it in there and hooked up but its not hard, hell even i figured out how to do it and believe me im not a mechnic
Go the 044