Trying to switch my odds brain from Hold'em to Caribbean Stud i came up with the following

Odds of being dealt any specific 4 of a kind

Start with 1 random card then (51/4)x(50/3)x(49/2)x(48/1) = 249,800 to 1

To hit Aces or 8's divide this by 6.5 (13/2) = 38,430 to 1

To hit any 4 of a kind divide by 13 = 19,215 to 1

I hope thats right but am fully prepared to be shot down in flames.