Ahh, so you DID tackle the left side valve cover! You're the man! Thanks for the info on the gasket. If you check your valve lash how about letting us know if you've got any out of spec or close to it. It's something that doesn't get checked very often so it would be good info to see what the results are for an example like yours with close to 100K on the clock. I haven't checked mine for three reasons - #6 bolt, not sure about gasket ( i hate scraping/cleaning!) and the #1 reason - what to do if I find one out of spec? I've got shims but that bucket depressor tool is big bucks for something that gets used once every ten years! You blew my first two excuses out of the water so maybe it's time to fab up a tool and dive on in...

RE: timing belt instructions - yes, I was faced with that dilemma because I went by Bart's excellently documented timing belt replacement (except for the radiator removal - I just yanked the hoses and upper fan shroud out of the way and left the rad in - there was still plenty of room to work) but when I got to the part about installing the belt on the crankshaft pulley I saw his instructions didn't jibe with the shop manual, the bulletin or the videos put out by Isuzu - so I went with what the manufacturer said. Bart sorry man but you got outvoted! Take a close look at the figure you just posted. #8 in the illustration shows a closeup of the dots on the belt lined up with tick mark on the FRONT of the pulley - #7 shows the notch at the BACK of the pulley lined up with the mark that is cast in the oil pump housing. Note that the notch lines up with the keyway on the crankshaft. Note that in the illustration, the keyway is 180 degrees from the dotted line on the belt. Now check out the pic of the crank pulley in your instructions and note where the keyway is in relation to the dotted line on the belt.

It obviously works with the crank turned 180 degrees from how Isuzu said to line it up though - so that must be one of the "valid" combinations - i.e., if you line it up the way Isuzu says to do it, then spin it a bunch of times, it eventually ends up with solid belt lines, cam sprocket lines, and head lines all matched up but dotted belt line 180 degrees from point of beginning on the crank sprocket. That's my guess anyway. It could be figured out mathematically but that would require someone with a lot more smarts than me!