Ok, I've read up on the subject, and can't find any pertinent information... I have a KA24E engine in my stanza, which is a 2.4L SOHC 4 banger. I've heard, but not seen that you can replace the SOHC with a DOHC with no other changes, but I find this hard to believe. Basically, I'm looking for ways to give the little thing more power. It's got 145hp and 153ft/lbs of torque now, so it can easily break loose the 185/70R15 tires. What else do i need to do to make it a DOHC motor? I'm not going to gain any torque out of the swap unless I change pistons, valves and the intake, but I'll gain about 9 horsies if everything just bolts together. Why am I doing this, and how do I do it? Also, my exhaust broke away from the cat on the front end of it... should I: 1. Replace the cat, and weld the pipes back together -or- 2. Get a whole new manifold back exhaust job done?