In a '87 B150 /6 Lean Burn, totally stock (apart from some option removal to simplify life, and rear brakes upsizing to potentially extend life of whomever is in front of me when I use them)

Check out the thing bolted to the head by the same bolt as the EGR amplifier bracket. (I'm uncertain weather it was on that bolt originally, or the one closer to the front with the ground lug)

Over the summer I made up for a good chunk of 10 years of neglect and procrastination. In so doing I learned what almost everything under my hood/doghouse is, but I still don't know what this is. (Not a stranger to cars...just slants and lean burn. I've owned this for a decade, but prior to this summer had done little more than keep it lubricated, running and stopping.)

Anybody know?

(Actually, one other thing that I don't know: what it is the ignition-module-shaped heat sink on the firewall with 2 wires)

This is a resistor that is part of the automatic choke pulloff system. One wire should connect to one of the field wires from the alternator and the other wire should go to the choke coil spring in the exhaust manifold. The wire heats the spring in the manifold to hasten the choke opening. Otherwise you have to sit and wait for manifold heat to do it. You motor (in most climates) only needs to be choked for the first 30 seconds of operation or so. Waiting for manifold heat alone to actuate the bimetallic spring to open the choke can take up to several minutes.

Keep this part and make sure it is working right.

The ignition module shaped heatsink on the firewall is probably the EGR dealy timer. A picture would help identify it for sure.

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Casually looking for a Clifford hyperpak intake for cheap.

"Almost" and "Yup" to Reed's answers, respectively. The round "flying saucer" is the choke thermostat heater (not pull-off) modulator. The factory electric-assist choke systems almost kinda worked OK when new, and are completely non-adjustable. The fully-Electric choke kits work better.

The 2-wire "looks like a mini ignition box" item is indeed an EGR timer. If no more EGR vacuum amplifier, then no more need for the EGR timer box.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Yeah yeah, thermostat, pulloff, at least I didn't say that he needed a vacuum line hooked to the one in the exhaust...

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Casually looking for a Clifford hyperpak intake for cheap.

Thank you.

I really need to check what the wires on the choke thermostat heater modulator go to. When I cleaned/repaired the harnass I had replaced some burnt wire and a 2-conductor pigtail with new wire and spade terminals.

I don't remember what I had powered the choke thermostat heater off of (that wire was also burnt off and the pigtial from the choke thermostat had snapped off--cheap Chinese aftermarket part.)

I should similarly check where the EGR wires run. I've been told that both the EGR and AIR diverter vacuum solenoids share a common hot wire and ground individually through the ESA. If that's correct, should the EGR timer wires both just run to the ESA, or was I misinformed re. the solenoid wiring?