Talking primarily about stock Mopar carbs.
I have been seeing a lot of different definitions of the terms
"Spread-Bore"
and
"Square-Bore".
I was under the impression that it is the size of the primary bore compared to the secondary bore holes in the base of the Carb.
I have recently read, only the Thermo-quad was spread bore because the rear butterfly shaft is longer on them. (?)
That kinda still goes along with my first impression.
It just eliminates some other carbs with a differing size bore pattern.
I used to think the AFB was square and the AVS was spread bore.
Looking at my stash of carb.s, I have both in the AVS variety.
Still guessing the older AFBs were square bore.
Which, which, is wich?
One fella even told me it was the bolt pattern.
That makes absolutely no sense to me.
Thanks in advance for clearing this up.