460 is the limit for stock springs and valve seals from what I have read.

Picked up my new motor yesterday.  It is missing the ZX distributor as well as the oil pump drive shaft.   Does anyone know if could I use the drive shaft from my current L24 motor?  If so, will it only work with my L24 distributor?  I've taken a quick look at the FSM, but I don't quite understand how it is all connected without seeing it in person.  

It should. Shaft sits in oil pump, pump connects to timing cover. Gear should be closest to the pump. Look at your FSM for timing.

#1 cylinder TDC compression stroke

Insert so dizzy tang is sitting 11:25 clock

I did the ZX swap into my 240 and used the original shaft, no problems.  Here's some pictures to get you familiar with what you're about to do,

http://atlanticz.ca/zclub/techtips/distributor/index.html

 

It'll be a lot easier on a stand than in the car, timing the oil pump and distributor shaft.

Thanks for the confirmation guys.  I think I will do the E12-80 swap on my L24 first and get it set up properly, then swap the new motor/ignition in the future.  There are so many variables that are completely new to me, and I can see myself screwing something up and getting completely frustrated if I do it all at once.

I found "my" best deal at amazon.com, newly reconditioned distributor with the E12-80 ignition for a '79 ZX $100.  Then a Crane PS20 1.5 OHM coil for $40.  That has been one of my best upgrades yet, it was like going from charcoal lighter fluid to gasoline on a campfire, they really made a difference.

 

You'll need a ZX cap and rotor too.