It's attached to the passenger side of the block... if you have a 5M-E. However if you've done a 2JZ conversion, you probably forgot all about the fuel filter and don't have one - like me!
I've been meaning to find a fuel filter with "plug and play" fittings for the 2JZ fuel rail OR the MA61 fuel tank. I suspect the MA70 filter may work (it mounts next to the tank) but I haven't had a chance to check one out yet.