the 02-06 sentra, and some year altima around the same years also will fit. the motor itself is the same, however, all the electronic connectors are different after 03.5 sentra. so to answer your question, a 05-06 qr25de will bolt into place but there are a few things, dont remember which, that will come from the 02-03, and some things from the 04-06. the 07+ qr25 is totally different. i remember the pcv hose on the intake manifold is different and a few other things.