So I changed my mind after some rumination. I decided to leave the head on until I pulled the front cover.

To do that, you need to remove the crank pulley (easy) and then the crank pulley hub (not so easy). There is some chevy specific tool for that, but I just grabbed the steering wheel puller, a wrench, and a breaker bar:

It was kind of a bitch. Someone put some black goo (looks and feels like black permatex) on one side of the shaft, and some orange looking crap (some soft of thread locker I’m guessing, but not blue/red locktite) on the other half. Once I broke that free it came off pretty easy. Then I removed the bolts in the front cover, and the two nuts and studs going through to bottom/oil pan.

Now I’ve already mentioned that I’m not all that familiar with Chevys, but I’m pretty sure this is incorrect routing for a timing chain.

(the missing portion of plastic guide was in one piece and came out with the cover)

I’ve got one of these:

…but it won’t fit in the spark plug holes, so that’s no help at all.

I’m not entirely sure what I’m going to do at this point. I don’t want to pull the head if I don’t need to, so I suppose that the best course of action is to get a timing chain, tensioner (and gears if they are supposed to be changed together), and see if I have compression. Not really sure yet. I need to do some research.