the SR20DET. i think it's soco or something, there's a couple that you can choose from. they also have the skyline engines and a bunch of others. but i'll be damned if your gonna fit a skyline engine in your 240 LOL, I've always wanted to get a 240sx and drop that engine in it for i've heard of great things about the swap..(fast). welcome to the forum, good luck, Jon