Exceptional one-handed-weapons/Armor = 500 (2h-weapons = 600)
non-exceptional one-handed-weapons/Armor = 450 (2-h-weapons = 550)
Exceptional shields = 450
non exceptional shields = 400
Edit: all jewelry exceptional & non-exceptional = 500 weight (there is a slightly lower success chance when imbuing properties on non-exceptional items.)
Always been like that, with the exception of 2h weapons, they were increased with item weight when the weapon revamp came out.