Don't worry, this isn't a newbie post (or at least I hope not:D)

I'm wondering the differences between the DOHC engines and SOHC engines of the varying years. I'm NOT LOOKING FOR:
Maf vs. Map, or CR, or which is better to turbo, etc (which is what I found doing searches).

What I AM looking for is mainly compatibility of components, specifically:
Types of Crank sensors used, I could've sworn there was a difference b/w the 99's and 00/01's, but I'm not totally sure.

Type of Camshaft sensors used (are the 99's and 00/01's different?).

Throttle position sensor compatibility b/w model years.
Or maybe even the compatibility of the previous gen 2.2L impreza sensors with the current (98 or newer) engines.

Or can anyone point me in the direction of who to talk to (the dealers in the area seem to be clueless)?

Thanks,

Jason

The crankshaft sensor is essentially the same, they seem to be interchangeable.

The camshaft sensor is the same except that there is an additional piece holding the sensor on the SOHC not on the DOHC (DOHC holder is machined into the head)

The TPS *is* different and incompatible but the DOHC TPS is compatible with the EJ22.

anything else? :)