As you all well know[*], there exist dialects of English that preserve vowel distinctions that the majority do not (such as "wait" vs. "weight", or "meet" vs. "meat").
Now, while reading a blog entry on the "Great New Zealand Vowel Shift", I came across an updated version of the standard lexical sets for English, labelled as the Revised Wells/Mills/Cowan/Rosta Really Universal, Dammit, This Time, Lexical Sets, in a comment by the famous John Cowan:
KIT, DRESS, TRAP, BAD, LOT, STRUT, FOOT, BATH, DANCE, CLOTH, NURSE, TERM, DIRT, FLEECE, BEAM, FACE, TRAIL, FREIGHT, PALM, THOUGHT, GOAT, SNOW, GOOSE, THREW, PRICE, CHOICE, MOUTH, NEAR, SQUARE, START, NORTH, FORCE, CURE.
For what it's worth, I (think I) merge the following: TRAP, BAD; LOT, CLOTH; BATH, DANCE, PALM, START; NURSE, TERM, DIRT; FLEECE, BEAM; FACE, TRAIL, FREIGHT; THOUGHT, NORTH, FORCE; GOAT, SNOW; GOOSE, THREW. I think I do not merge CURE with NORTH/FORCE(/THOUGHT); pour/poor are distinct from pore and paw (which are identical).
Caveat: my 'lect is non-rhotic but I do have linking R (and occasionally even intrusive R), so "my pore is" and "my paw is" would (usually - when not inserting intrusive R) sound different even though "my pores are" and "my paws are" would sound the same.
[*] It's a joke, son.