Originally Posted by Scarebird
this is a bad idea from several angles:
1. 1979 Seville rotors are 5 on 5 bolt pattern for starters. And they are 11-3/8" in diameter. Your 81 Monte rotors are 10-1/2", so you will easily lockup the rears due to grooss bias mismatch.
2. Crossdrilled are ridiculous for the street; they are guaranteed to crack from stress risers between the vanes.
He probably has WS6 Trans Am rotors (5x4.75). Similar setup.
Holes = cracks - slotted or solid is the way to go. Modern pads do not outgas like pads of the olds days.