Help!

I bought at 300SD that ran really rough. Eventually died, I adjusted the valves. I checked the compressions with the following readings 380 psi; 140; 320; 360; 350 psi.
Obviously #2 cyclinder either has bad compression rings or the seats are bad. I figure first step was to pull the head (hoping I just can replacethe head). My general manual doesn't explain the steps very well.

In order to not have to mess around with the timing, can I wire the chain around the top sprocket. When I unscrew the bolt to take the sprocket off, is there only one way that sprocket can go on ? (so when I put it back, the timing will be right).

Is there anything I need to be careful of ?

Scott
PS: I bought the car cheap. Body is in great condition. I have time but no money. I figured I would give this a try. Any help is appreciated !!!