rear brake size...97 v6(se9)

[U_V6]

calipers are different. 284mm discs have 54mm piston calipers, 288mm discs have 57mm piston calipers. and brake pads also are different. what can or cannot be swaped - I don't know.

[GreyDJ]

The top picture from a box is the part number for a pair, the number stamped on the disc must be the number of a single disc.

[Fraz]

top number says disc set rear C20LET C25XE X25XE

The one on the dsic I make out to be 9037551..no part
then tried a 8 on the second 5 and also a 9 ......no part

[k1nty]

that second photo was same as mine....270 mm