B18C5 is the type R motor. Sweet motor, but I think it also has the highest CR out of the B series. Then there is the B16B, the Civic type R (CTR) motor. The cams in this head are the largest, even bigger than the ITR cams. The CTR and ITR motor are almost the same price. If you go with the LS motor, get the B16A, or A2, head. It has the best flow next to the ITR head, and is much cheaper. I blew my B16A2 and got a B16A installed for around 3K, including new clutch, flywheel, Skunk 2 cam gears, and many more. Ask for Tom at Honda and Acura Specialists in Jonesboro. He knows his shit.