a pump out of a ecr33 gts-t will be your easiest pump to install (rb25det). goes straight into the standard housing, the old pickup even goes on, good for 200kw @wheels in a r33. Gtr pumps won't fit straight in as they have a remote pickup, walbro only make one type of pump that i know of. there about the size of a peanut, they must have some pretty kick ass technology, cause when you compare em to a stock nissan pump visually, you'd think its a down grade if anything. if your gonna get a walbro, make sure its authentic, lots of chinese imatation stuff out there that'll last 2 days. larger flow rate is fine.