My 87 carbed CRX HF has a special distributor with an extra pigtail connection for the internal advance controller. The 87 HF vacuum advance only has one diaphragm.
There is also an ignition control module (small ECU type box) under the dash of the 87 HF (separate from the ECU under the passenger seat) that controls timing.
Most of the above parts in the above pic came out of my 87 CRX HF. The ECU is on bottom, the black box is the alternator control module and the gold box above it is the timing control module. The small black sensor on top is the barometric pressure sensor, the semicircle is the VSS pickup from the speedometer and the small board with the yellow connecter is the shift light circuit board.