Oh, btw, that 3-hole flange under the exhaust manifold ( in your first pic ) is an odd-ball. Exhaust shop is unlikely to have it.
@ToyotaMatt sells a kit, should you want an exhaust shop to fabricate a new downpipe that will work better...
It's a Hot Air Intake, supposed to help warm up when engine cold by diverting hot air from around the exhaust up into the air cleaner - However, the round thing on top of the AC snorkel controls a flap inside that closes off intake from the normal ambient air when cold start, then supposed to...
A few overall pix of the engine compartment from different top angles would be a good start.
(Hint: Silver star membership will allow you post unlimited pix far easier, for only $20/year and avoid all the pop-ups ;))
There's a thermosensor for carb fan on the manifold (at 9 o'clock). Not found on a '74. Either someone put in a different engine or swapped in a later Intake/Exhaust combo and tried to adapt the existing down-pipe. More pix would help.