[Oregoon]

The reason you're finding intakes and headers for '74 and earlier is that '75 and up used an integrated head where the intake is part of the casting, whereas the earlier motors have removable intake and exhaust manifolds. Also, most of '74 engines I've seen had factory unleaded-valves. Of course, given that we're talking about trucks that are around 40-years old, it's not uncommon to find that it's already had a head-job at some point... As for your 292, I've seen both integrated and non-integrated heads on them, and there's a lot of conflicting information about which years did and didn't use them on the 292. Regardless, the availability of interchangable heads and the time-frame make the point moot.

The integrated heads are known for cracking, and are often swapped out for the earlier 230/250/292 head, which are interchangeable. In fact, I think it's only the 194 head that features a smaller combustion chamber, though it too will bolt right up and is a popular way to raise compression.

As for recommendations, Clifford Performance offers a water-heated intake that takes either a 4 or 2 bbl, with a matching header. A bit spendy, but worth it if you live in a cold place.

As to the way your truck is running, it sounds like a clogged idle-circuit or a problem with your float. Does it behave like it's starving for fuel?

I chased a similar problem on my 250 and it wound up being as simple as a partially clogged fuel filter not allowing the float to fill back up after I'd ran it wide-open. It started fine, ran well, but would die as it came back down to idle. I played with float-settings, blew out the passages, fiddled with timing, and scratched my head... Then, I put a new fuel filter on it and laughed at myself!

Hope this helps. Good luck and congrats on your new truck!