Nothing earth shaking here, but maybe of interest for a Saturday Afternoon. Mainly posting because no one else is.
I've had a Howell TBI kit for my J20 since last year, and just now getting to install it. Removing the air injection system (smog pump, "Air Guard") worried me. Now it's done and it was no problem -
The plugs I used were from McMaster-Carr https://www.mcmaster.com/50925K435/ - I removed the o-ring and added a copper washer from a kit I bought from Amazon https://www.amazon.com/gp/product/B07G5 ... UTF8&psc=1
I first sprayed the fittings liberally with PB Blaster - only because that's what everyone says to do. Remembering what my mechanic friend would do for exhaust bolts, I got the manifolds as hot as I could by sitting at part throttle (maybe 2500?) for about 10 minutes. (He would zoom out and back a few miles on the nearby 57 freeway). This likely burned off all the penetrator (smoke!)
I then used a 6-point socket on my long 3/8" flex ratchet and they came out without breaking. Took some persuading to get the socket fully over the air injection fittings; once they were on, a little muscle and they loosened. I went around and got them all broken loose before they cooled much. The rearmost on the passenger side can most easily be reached from the ground.
Here they are on the bench -
Look pretty good. I recall I replaced the check valves and smog pump long ago. This truck has had working air injection all the time I've owned it.
Removed stuff - more to do.