[d.a.autry]

That's what I'd try to do (just look to see a piston coming up) once you remove the plugs you can pretty much feel any major mechanical interference as your rotating the crank by hand.

Look to see a piston coming up and then back off until you see that piston go down far enough to rotate the cam and actuate the valves.

Like I said, usually interference engines will suffer, but then someone, somewhere ends up winning the lottery eventually. You've got to fix the crankshaft pulley problem anyway, and it only takes a few quick checks after this is done to see if you might possibly be a winner.

As far as in the '88 head I don't know. I do know that parts lists show a different # for the '88 (944-104-033-08) and the '89's have a different # too (944-104-040-02).

I do know that since cylinder head # 944-104-303-7a (this # is per the service manual, don't know why there is a difference in the 3rd set of #'s) that one difference is how the spring seat is machined. The spring height was the same but I don't think the later ones needed shims when new.