There's a member here who has a friend with an 80 Mirada that runs in stock.
360 4bbl combo. They bought it as a used stocker and built a new motor for it.
A nice basic build, no voodoo, just proper machining and attention to detail. A good cheater cam, decent converter, etc......... Ran well into the 11's right off the bat, about .500 under the index. This is an 8.5:1 360 with 1.88 valve heads.

The thing pretty much all stockers have in common is(with the exception of Hemi/MW cars, bb Chevy rect port head motors, 4bbl Cleveland fords, etc) is they have small heads and dual plane manifolds.
Sure, that stuff is only going to get you so much performance, but it usually has way more potential than what most people think it does.

As an interesting side note.........bracket guys look at stockers and just assume it's all cheating and voodoo, stocker guys look at bracket cars and wonder why those cars don't go faster with aftermarket heads, big cams, manifolds, carbs, etc.

It's all perspective.