i need the size for rear calipers on my 92 classic. i went to the shop and they had 2 different sizes...im guessing one for ABS and one for without ABS.

They will only have one in stock I bet. I have yet to see 250mm brakes on the rear of a SE-R/NX. Get the 234mm's. They will have two listed but since no one carries the other one in as a core exchange I doubt they will have them.