IronMan, the balance shafts were there for a reason. The technology was licensed by other manufacturers, including Porsche...for a reason. Some will say they cannot tell the difference when they are eliminated, but there will be a balance problem that is inherent with a four cylinder engine. I'd always choose to keep them.
Heath, while the 2.4 is a great engine, keep in mind that it's not always as easy as it seems to swap one in. I've never fully integrated mine into my '86 Montero, and I wish I had just pulled the 2.6 and sealed it up and left it alone. Seriously. Even though that truck had the early 3-speed auto, at least it was a complete running vehicle, while it is not as it sits (and sits) now. The truck has been in the east valley at LordTrunk's house for a couple of months now and it still has a list of things to be done to it. Not the least of which, the a/c compressor for the Montero does NOT bolt up to the 2.4, so that whole system has to be grafted; an expensive and extensive conversion that also seems sort of essential here in Phoenix.
Thanks John. I'm always in favor of retaining engineered components/systems. I was just checking to see if there was something I missed in regards to efficiency, or well documented failures, etc.
I think I have a plan, and a clear path at this point. Only thing left to do is get the motor apart, and see what I'm working with.
Thanks to all for the helpful replies.