by m880cummins » Wed Nov 13, 2013 7:20 pm
You need the 1.5" rotors.
They switched in late 1989. Trucks with the big Selectro style external lockouts had 1.25" and trucks with the warn hubs like yours had 1.5". They are the same as a Chevy rotor.
Charlie
1977 M880 Cummins 5 speed SOLD
1985 Crew cab Cummins P7100 NV4500 D60/D80
SUNY Maritime Class of 2017!