Only the L88 equipped Corvettes needs anything higher than 98 RON (today's 93 AKI) but they really weren't seen on the street too much.
In the early 1960s, "fast" cars were built by people who knew how to work on cars and usually accompanied by an engine swap. A bud had a 50(?) Chevy convertible with a 348 3x2 and there were a lot of 55-56 Chevies with 327s.
In the late 1960s, anyone with good credit could own a muscle car. A guy who couldn't change spark plugs bought a 289 Mustang and whipped most of the "fast" cars in the area. I guess that didn't sit too well with the guys who used to rule the streets when their engine swap and hard work was beaten by a factory muscle car.
My 66 Corvette was a 327, then a 350, next was a built (not by me) 396 with aluminum rectangular port heads. It was a junkyard engine which died shortly thereafter. Fortunately, I hadn't sold the 350, so it was bored and stroked, heads flowed by Tony Feil. The stroked 350 and 396 would knock on any less than Sunoco 260 or Amoco. The 427 Camaro was a beast. My mother once said I would never own anything but a fast car; thankfully I proved her wrong.
Things are different today, but in it's day the 103 was needed. Now, we have knock sensors and modern electronics which change matters. However, if the only gas available is 91, a blower motor will have less than one fed 93. Meth/water changes that, but adds another 3-5 to the bill and another dyno pull.
Although you are correct, the L88 Corvette Corvette wasn't that common. Probably more a result of the option costing over $1K than lack of desire. OTOH, there were cars which could beat them and by a couple of lengths.
I've never been a member of AA, but I am a reformed street racer. If someone aggravates me enough, I still will get on it; however, not for money. We have a deal, she supports my insane love of recoil and torque, but no money racing.
Paul,
It was a special time. I sounds as if we could name a car then self kick ourselves for passing it by or selling it.
Hemis were and are special. I shyed away from them as except for rejetting and changing the advance curve; modifying them was a lot more expensive than GM, Ford or anything Chrysler corp made except the Hemi.
Most of the ones I owned were as the saying goes were bubba'd. Back in the day there was two types of Corvettes; the first was an unmodified car and the second was called a driver. My 66 was a driver, or no numbers matching. A 350 replaced the 327, an M22 replaced the M21, and a 4.88 replaced whatever was there. Depending on one's interest either could be worth more than the other.
The Corvettes went bye bye with kids for a new to us 84 Z28 which lost the 305 for a 350 with a bottle and the whatever was swapped a 3.73. I bought the 97 a while ago and the centrifugal is waiting for plant shut down.