Well your pics are of 2 different alternators. One looks like an older SI and the other a CS. Both are internally regulated so it looks like the required wiring mods have already been done. You can exchange the older SI for a rebuilt or go with the CS. If you use the CS you obviously have to replace the pulley. Not sure on the alignment of the pulley with the water pump pulley, may need to do some adjustments to get the proper alignment but will work. Looks like the clocking on the CS is correct, the mounting tabs. The CS will have a higher amp output so if you need it, that would be the way to go. If not then the SI is a pretty simple swap. Have the CS tested first if you want to use it, just to make sure it's good.
__________________
Hank
70 Chevelle SS396(454), M20, 3.73
My Chevelle
|