I think that Oldsmobile was also tinkering with a hemi design in the late '60s or early '70s. Around 1970, the insurance companies quit insuring young guys with the high hp cars and it was too costly for anyone else. Then with emissions and the gas crisis, the hp went away and there was nothing decent to buy, horsepower wise, for many years. The muscle car era was over. 1985, with the L98 was the start of a whole new muscle car era but GM only put the good engines in the Corvette, Camaro and Firebird, leaving the the mid size cars with 305s.
I had a '84 HO 305 Trans Am and it certainly wasn't going to give anyone an adrenalin rush. The L98 would definitely have been a step in the right direction. Don't count on GM knowing much about what us guys on the street are thinking. They come up with something, throw it at us, then hope it sells.