Alright, I had this 2litre on an engine stand and did the pushrod tube seals and everything else. I put it in and ran it and two of them started leaking. So I figured I could snap a couple pics of how you change them out because they are way easier than a type1. This is a used motor, yes the head is "brown", oh well. It runs way better than the GEX motor it is replacing. This is my first tech article so bear with me, maybe someday I'll get a camera person.
Here's the tools you'll need:
Typical leaky pushrod tube, pic taken after install (notice the yellow snot) but the oil drip is from before when it was leaking. I cleaned it off afterwards and it hasn't reappeared.
So, pop the valve cover and check out what you have. Two rockers and a spring clip. The clip holds in the pushrod tubes and has nothing to do with the valve train.
Remove the spring clip, then the rockers. The rockers should be held on with 11mm nuts and washers, these are special so don't lose them! Put the rockers in your valve cover on the same side they came off so you don't mix them up. Put the spring in there and the nuts and washers too so they don't get lost.
Now take out one pushrod at a time and put it in the valve cover while you're working on that tube. Grab your snap-ring pliers and put them in the tube like so, and twist and pull at the same time and the tube should come out, sometimes they need to be coaxed with channel locks from the bottom but be careful not to dent the tube.
This is a 1979 only (I think) pushrod tube because of the square ports on the exhaust/heater boxes they made it a little smaller in diameter for the first few inches.
Put the new o-rings on and hookup the inner and outer o-rings with some Gasgacinch. I didn't do it with the snot the first time and they leaked, I recommend using the snot.
Then grab your small engine spark plug socket, some of the tubes need an extension to get a good hitting point. The socket fits in the big tapered end of the tube, but doesn't fit through the tube. Use the small hammer and gently tap them in, using one hand to guide them into the case. The key here is to be gentle and not screw up the tube. Once they are seated in and against the case you will know. I didn't get a picture of the tapping in part but here is how they seat on the outside of the head. There is a little RTV from some people years ago that gooped it on the outside instead of taking the time to do it right. I even used the parts washer to clean them but this little bit wouldn't come off.
Put the rockers back on with the slots facing down, put the pushrod retaining spring back in and torque the rocker nuts to 10ft/lbs. Put the valve cover on with a new gasket and some grease so it won't stick or leak.
All of this took about 20 minutes. Hope this helps somebody!