[Barcochris]

I have a standard alternator that has been converted for a 100 amps and one wire. People tell me that I need to have a deep grove pulley on it. Anybody know were I can get one or the numbers on it?

Edit: How do I know if Mine is a deep or not?

 

[anychevy]

People tell me that I need to have a deep grove pulley on it.

They were factory fitted to alternators on solid lifter engines to prevent throwing belts off at high RPM and not really necessary otherwise.

 

[1Fast7D]

Edit: How do I know if Mine is a deep or not?

With a deep groove pulley, the belts sit deeper in the pulley. Below is a pic of my 72z with factory deep groove pulleys (only PS and water pump pulley is shown in pic)

On a factory deep groove alternator pulley, it is also slightly larger than the standard pulley. (I can take a pic if you need one)

You really only need deep groove pulleys if you are having trouble with the belts staying on.

 

[zookpr]

Another thing to consider... Once you add one deep groove pulley, you need to have the entire set for all locations otherwise the belt will ride to one side since the centerlines of std depth pulleys ARE different than deep groove pulleys. You be fine with the standard deepth pulley. Later GM application with hi output alternators used flat mini-grooved pulleys on the drive and driven locations. These can be seen on trucks/suburbans. Again, more special pulleys.

 

[SWHEATON]

If there is a std size pully currently on the alt make sure the belt is in good cond and tight & then try it out to see if there is any slippage/squeeling when your 100amp alt is under a load and charging .

If not then dont worry about it but if yes then you will need to upgrade to the wider pulley/belt system for the alt like was used on an 87-88 monte ss for more belt area contact on the pulley as already mentioned.

March Pulleys likely would sell something that would help you out in that case.

Scott