What would your fantasy garage look like? While some people might fill theirs with an eclectic bunch of cars from different eras and countries, each offering a totally different driving experience to suit a different mood, others are completely fixated on one specific model.

Chuck Cocoma definitely falls into the latter category. The guy is obsessed with the Pontiac GTO, and has been for decades. He bought his first brand new in 1964, but really fell down the rabbit hole in the early 1980s when he started amassing the collection of GTOs that’s due to go under the hammer at Mecum’s 2023 Kissimmee sale.

Cocoma has other models, and other GTOs, in his 40-strong car collection, but what’s special about the nine GTOs heading for Mecum is that they’re all powered by one very specific type of Pontiac V8 that was only available in 1969 and 1970.

Called the Ram Air IV, it displaced the same 400 cu-in (6.6-liters) as the base GTO engine in 1969-70, but featured a hot cam, aluminum intake manifold, free-breathing exhaust and snorted air through a functional hood scoop you could open and close via a knob on the dash. You could only order it with a steep set of drag-strip-friendly rear-end gears that would have made freeway driving torture, and air conditioning was a no-no. This was for serious drivers only.

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Most casual buyers would have been put off by the restrictions listed above and that fact that on paper the RA IV cost far more, but only officially put out 4 hp (4 PS) above the mid-spec 366 hp (371 PS) Ram Air 400, which was a white lie on Pontiac’s part.

And the RA IV looked even less enticing in 1970 when a pair of 455 (7.2-liter) V8s joined the options list. GTOs equipped with the hot 400 were faster down the quarter mile, but the 455’s massive 500 lb-ft (678 Nm) of torque made it easier to drive and feel faster in point-and-shoot situations. And then there’s the price: the 455 cost $58 and the RA IV was priced at $558 over the base 400 cu-in (6.6-liter) engine, plus another couple of hundred for equipment that Pontiac made you order with it.

Which is why fewer than 1,600 Ram Air IV cars were built over that two-year period, including Cocoma’s 1970 Orbit Orange GTO Judge convertible, one of seven cars built in that spec. That particular Judge will be the headline attraction when the collection goes to auction because of its rarity and its punchy color scheme, though a heavy, fully-optioned convertible with an automatic transmission was a weird home for the race-ready RA IV motor.

But there’s another car in Cocoma’s collection that perfectly sums up what Pontiac’s engineers had in mind when they created the engine. A 1969 non-Judge car equipped with a four-speed manual transmission, it was very lightly optioned when new to keep the weight down, meaning it doesn’t have the hideaway headlamps and rolls on steelies wearing simple dog-dish hubcaps. This unassuming blue coupe was clearly specced to go as fast as possible.

One you start diving into the spec of each car like this you realize that what appears to be a collection of identical old muscle machines at first glance is actually a surprisingly diverse collection of vehicles that each have a different story to tell, whether it’s how they drive, or what they’ve been through in the five decades since they were built (most are restored, but one is a true survivor). Well, we bet that’s how he tries to justify it to his wife, anyway.

So if you could only build a collection out of one very specific kind of car, what would that car be, and how many examples would you need to have to show every side of that model? Leave a comment and let us know.