Well I went over there and changed out the L18 head gasket, Glenn is a funny guy to hang out with, he gives you shit and receives it without too much complaining.
First thing I looked at was the intake side chain guide, it looked bent to me, I bent it back once the head was removed, I also looked down in there and could see the post at the bottom, the chain made that familiar curve it makes, it did not look like the chain tensioner had come out of position, my wedge fit in there perfect once I cut an inch off the end as the L18 is shorter, so I went forward thinking there was nothing wrong with the chain., once the head was off it was obvious what the issue was, a giant piece of gasket was missing from the cylinder to the outside of the block, I spent a lot of time cleaning the block and head surfaces, I also used the set of head bolts I brought with me as his were covered with what appeared to be some kind of sealer or gasket material, we had to pound one of the head bolts out of the head as it would not spin out, I ruined a screw driver getting it out and then we used a drill bit to open up the holes in the head till the head bolts slid in and out without restriction, the driver side head bolts did not unscrew out of the block easily, none were loose but the rear pass side was not all that tight either.
The head looked fine in that area, but the block was rusty and pitted where the head gasket was missing, I cleaned and cleaned the best I could and put the head back on, it went on smoothly without any issues, we put it back together using a new intake/exhaust gasket, I cleaned them surfaces also, this W53 head had no coolant holes.
When we started it it didn't want to start, it took a few times to get it going, once running it did not run very well and would not idle, it was missing badly, I figured out that #2 plug was not firing, I had that valve cover off that engine several times checking the valve lash by feel, none were terribly tight, it sounded terrible, I fiddled with the fuel mixture and got it to idle fairly smoothly but it just didn't sound right, I used another spark plug wire on #2 plug and that changed nothing, but eventually #2 plug started firing using the original wire, but still the engine sounded wrong, I figured out that somehow I got the cam gear installed 1 tooth off so I fixed that, maybe it was off all that time.
The more we worked on it the better it idled, but the engine was very noisy like the valves were too loose, I fiddled with the distributor timing but that was confusing, you see it appears to have an L20b plate, but an L16 pulley, I just adjusted it to where it idled best, it will idle near 700rpms but it just didn't sound right, I did forget to bring a straight edge to check the block and head, it did not leak coolant into the oil or blow coolant out of the radiator, it really does idle very slow but it just don't sound right, but I am comparing that to my work truck engine, mine has dual SUs and his has a Weber, not sure how old the fuel is in the tank, but in my experience these engines will not run on spoiled fuel and he said he had added some a few months ago, in the past when I had fuel spoil adding new fuel only ruined the new fuel, it would still not run, in the end just before I left it started easily, it just seemed very noisy to me, it revved fine but seemed to have an extended/long/slow un-revving, I don't have a word, it un-revved slower than my work truck engine, but this is an L18 and mine is a LZ23.
I expect the first thing I would do is new plugs to see if that helped, next I would either rebuild the Weber carb or at least clean it out, I really don't like down drafts, either they run great or they need replacing, I prefer Dual SUs, I understand them.
If it were my truck I would likely drive it around for a while and see if it improves, I would check the valve adjustment, do a tune-up also, I might even try sucking fresh fuel out of a gas can to see if the gas is part of the issue, it needs timed also, I could do that driving it, but having mix matched timing marks is very confusing, I left when I had done all I could think of.
I really do not understand how people put up with that traffic on the freeways in Portland, they need minimum speed limits and then start passing out tickets for those not doing the minimum, after a few tickets either they will do the speed limit or quit driving during high traffic times, I hate Portland traffic after 3pm.
Here is a photo of the head gasket.