From R12 to R134A needs to evacuate and flush the system, replace all O- rings(preferred), replace drier, replace with R134A compatible oil or oil that comes with the new compressor.

What is the displacement of the original compressor? Sanden-508 means 5 pistons with 8 cubic inch/r of displacement.

Will the new compressor fit your car? it may hit other parts even with a modified bracket.

What type of pulley? newer types of compressors usually use serpentine belts.

The new variable displacement and scroll type compressors provides jerk-free, easy drivability, and fuel economy but....