I have a new crate BB and an SI alternator. For some dang reason the BB came with a 7/16 threaded hole for the pivot whereas my alternator has a 3/8 hole. Can I just drill the alternator and bend open the little spacer bracket that fastens to the alternator and go with it. Or do I need to do something else???

Ill take anyhelp I can get cause I dont know wtf I am doing. Every little step of the way has been interesting on this project.

Thanks
Dave

Hey Dave, The original big block long water pump setup used a double ended bolt for the alternator pivot, it has 7/16 threads on the end that goes into the head approx 1in long and a long 3/8 stud that goes through the alternator and spacer.
I couldnt find one when I put a Big Block in the 71 so I got a 7/16 bolt and a long 3/8 bolt, I cut the head off the 3/8 bolt and welded it to the 7/16 bolt. I ground the tip of the 3/8 bolt to a point and drilled the 7/16 bolt in the center of the head with a 7/16 drill just deep enough to make a divot so there would be plenty of room to weld and grind smooth.
I'ts held up for around 10 years or so.
You might check the Chevelle catalogs, They may have started making them again.
Bret.
I just checked, Ground Up has it, pn BN-339 for 8.95

I would just drill out your alternator and use all-thread from a hardware stor like this: There are 3 nuts. One against the head, and 2 sandwiching the alternator. That way it is adjustable to keep belts aligned.

Hard to tell from the pic but its there:
http://i52.photobucket.com/albums/g34/Brettd85/DSCN0817.jpg

Dave,
Bret is 100% on the money.
Order the correct bolt/stud. :thumbsup:

Hardware store all thread will work but it's pretty soft stuff for the job.
http://www.ss396.com/mm5/merchant.mvc?Screen=PROD&Store_Code=chevellecamino&Product_Code=BN-339&Category_Code=

There is a spacer that goes between the alternator and the head also.

Thanks guys. I found one at NPD near my house here. I have the spacer part.

You guys ROOOCK

But why GM does stuff like this?

Dave