What's the longest a Crazyhouse game last?

I know that the length of a chess game is limited by the 50 move rule, however in a Crazyhouse game it's possible to avoid having a game end with the 50 move rule by dropping pieces and then recapturing pieces.  This means that if the only other rule that limits the number of moves a crazyhouse game can last is 3 fold repetition then the number of moves a Crazyhouse game could last might be close to 3 times the number of reachable positions in Crazyhouse, and the number of reachable positions in Crazyhouse is much larger than the number of reachable positions in chess.  So my question is what's the longest a Crazyhouse game could last in terms of number of moves?