I may just be demonstrating my ignorance, but it isn't it the same basic car? The 917 was the road racing version. I know the 917/30 pictured had the baddest engine they ever built. I was always partial to the closed cockpit models.
You’re right. There were so many variants. The long distance road racers had different wheel bases, smaller less powerful engines and different aerodynamics, but they were all 917s.
The Can Am series was my favorite series at the time. It was basically no rules racing except for safety and full fenders. Big block aluminum Chevrolets with Hilborne fuel injection were dominate before the Porsche showed up. There was just so much innovation from talented individuals before really big money killed it.
Jim Hall’s Chaparrals were always cool. He fielded one (2J) that employed an auxiliary snowmobile engine/fan that sucked air out from under the car to generate downforce. In theory, it would have stuck to a ceiling. It got banned for picking up loose asphalt and pitching it back at any car following.
I was lucky enough to attend a race at MIS in 1969. One of the orange McLarens (Bruce McLaren) won that day, but I was pulling for a new Boss 429 based 8 liter iron block powered Lola. It broke, but so did the fastest car that day, a Can Am Ferarri.