$8,109.70 in 1978 is equivalent to $32,329.10 today with inflation which is not too far off from what you can buy a similarly equipped single cab pickup truck today. When I mean similarly equipped, I mean the exact same features, not trim packages. Most trucks were single cab back in those days.
According to GM website, you can get a regular cab 1500 4wd with a 355hp/385lb-ft 5.3L V8 for $32,590 and I bet it has all the same features as the high end trims back in those days. I bet that it also tows more and gets better fuel economy than those trucks did too. So the problem is not that the same trucks apples to apples are more expensive, it is that people want more in their trucks like crew cabs, fancy tech, and power engine options that can tow way more than what trucks can tow back then. Heck, you would have to get a class 6 or 7 truck back then to tow what class 2b and 3 trucks tow today.
