Hi guys, does the lwr mounting use a stud or a bolt. All the books show a stud ,but it has a 7/16 size which does not screw into my head. Thanks for your help Joe.

The stud is 3/8, like a normal intake bolt.

More info including where to find one in this thread.

http://www.camaros.net/forums/showthread.php?t=63795&highlight=alternator+stud

Thanks for the reply, but i am talking about the lower mounting of the alt.
Is it a long bolt like a small blk or a stud tha screws into the head. I have a stud but one end is 7/16. Thanks Joe

Oh, that location. It's not a bolt like the SB, tt's a long stud that has threads sized for the head on one end with an attached hex head to tighten it to the head. Over the stud goes the rear brace bracket, the long spacer, and the alternator. Then the front lower alt backet (to water pump) and finally the nut. I'm not at my car right now, but 7/16 on the front (toward radiator) side may be right.

You can see it in Rick's on-line catalog, part # AB-14

The stud is correct. It is 7/16" on the head side, and 3/8" in the big end. I have Brodix RaceRite heads which claim to be an exact match to the stock head. The only exception I took is the idiots drilled and tapped the hole for the alternator 3/8" instead of 7/16" like a stock head. When I called them, they said that was the indrustry standard size hole and to "get over it". I just hung up the phone shaking my head... wow, what a moron...:noway:

Thanks guys great help as always. I guess i will drill and tap out the hole. The other 2 holes on the head are 7/16, the bottom and inside one, but the top outside is 3/8. Thanks Joe

Do you have the front lower bracket and have you mocked it up? As I said, I'm not at my car, but I am looking at the pictures I have and I think the stud goes in the upper hole closest to the valve cover, which you say is 3/8.

If you're talking about a 69 (pass. side alternator), I've gone through this. Yes, most after-market heads are tapped for 3/8" bolts for all the accessories. All you need to do is purchase a long 3/8" bolt (7"?) in grade 8 and sandwich everything together.

Also, I hope you're not using any aftermarket alt. mounting brackets. For a BB, I purchased a repo lower bracket that was off (incorrect hole spacing) and had pulley alignment problems, until I found an original GM.

Good luck!

I am using gm brackets and pulleys, just trying to keep it stock as possible. I will drill and tap out hole to 7/16". Thanks for all your help.


Joe