The TSRM for the '86 MKII is available for viewing online. I hope it covers what you need. I know the diagnosis system is different in earlier years though.
Here is the link to the section for working on the head:
http://www.cygnusx1.net/Supra/Librar...ection=EM&P=18
I hope this helps.
As for timing, resetting the mechanical timing is simple enough and you'll find it covered in that manual in the Engine Mechanical section and Ignition System. I do not know the procedure for setting the ignition timing, although you should set it after you reinstall the timing belt.