Alternator Bracket Location

It depends on your year car.

Ideally what you want is the correct set up for your year car with a small block. You need the waterpump and crank pulleys; and the alternator brackets and spacers from a NON AC car.

You should be able to use a stock belt length.

Keep in mind if you try to find used oem parts you'll likely only find dual groove crank pulleys - but these will work fine, just use the correct groove which will be the first groove moving from front to rear, the singles are probably rare as hens teeth. You could buy reproductions of all of these parts as well for $.

The water pump pulley is unique to non ac cars as well, they are larger in diameter and the back spacing is different.

Now, my last comment - did you install a NON ac water pump ? This is critical. The non ac water pump pulley is larger in diameter - it slows the pump speed, however the impeller in the non ac pump is larger in diameter than the AC pump impeller and pulley. Important for proper cooling. Dont mix and match these - you'll have an overheating problem.

Happy hunting!