Suits do NOT help determine the winner in Stud high or Stud8, but with regards to flushes, RANK does help determine a winner. So if player 1 shows A
for his/her best 5 cards, and Player 2 shows A
for his/her best 5 cards, then player 2 wins because his/her first 3 cards match player 1 in rank and the 4th card is higher in rank.
In reality, this stud/stud8 dabbler may have gone to the 3rd card once or twice, but that's as far as it has gone.