Setting up timing on disturbed engine

[kahng@nimo.com]

I took of the head of my normally aspirated KZ engine to replace the head gasket
and removed the cam to replace the lifters and two broken exhaust studs on
number 5 cylinder as well.
I'm putting it all together now.  Here's the question. Since the cam timing and
distributor have been disturbed from the cam removal, how do I make sure that
I'm not a tooth off when I put the timing belt back on?
The number one piston has remained undisturbed and is at TDC.
My Haynes manual (sorry no Bentley) says to line the mark on the back of the
timing gear with the gasket surface of the head, however, this does not seem
very accurate.  Should I take a straight edge from the top of the head and make
sure it is exactly in alignment with the dot on the back of the cam gear?
Next question is regarding the distributor.  Since the number one cylinder is
exactly at top dead center, I assume that the rotor has to be facing 180 degrees
out from this (opposite cylinder) since the number one piston is just beginning
its intake stroke.  Any help would be appreciated!

Jerry