Not so much. The smaller bore engines were easier to clean up the emissions on with the technology of the time.
Back in the day I used to read articles where because of the difficulty in getting a stick-equipped vehicle past emissions
(compounded by the low percentage of overall sales) there was a time where supposedly no stickshift vehicles would be
offered at all. We tend to forget that back then it was a struggle for them to meet the constantly tightening emissions
regulations with the technology they had plus learning as they went against tight deadlines.
You sure it was the bore? There was some sort of mpg driven 5.0 liter limit imposed at some point in the malaise era. Not sure if there was a smog/guzzler tax beyond that or what.
I seem to remember that once upon a time that on a per vehicle basis EPA testing was that a 15 mpg rating = gas guzzler tax?
But 16 mpg = good to go? But after going over a certain GVWR (> 6000 lbs?) this no longer pertained?
NOTE: I think the current go/no-go gas guzzler tax currently starts at 22.5 mpg and progressively gets much larger?
EDIT: And I seem to remember that back then GM didn't want sell any vehicle that would run afoul of the gas
guzzler tax, partly due to the financial penalty, and also didn't want to draw negative press to themselves for
demonstrable indifference to mother earth. The last time I bought a new vehicle (admittedly a long time ago) I think
the gas guzzler tax was something on the order of $750. But that was long ago, see attached for a
more recent table. (Taken from the following
article.)
It's been a long time, so the details are a bit fuzzy now. :0) But I do remember that the goals
of both meeting stricter emissions + also meeting CAFE standards = burning the midnight oil for the
powertrain engineers paid to worry about these things. And some (desirable to me) combos were no
longer offered for sale for running afoul of one or both of these mandated standards?)