Finally.....The Correct Size Alternator Pulley
 

The Correct Size Alternator Pulley is about 2.75 inch OD on the face....This ALL Aluminum Pulley is very light and just a tad larger yet very close to 2.75 inches diameter. It is a little Pricey from Summit Racing. The Installation is very easy with my 15/16 inch modified Open End Wrench and 5/16 Allen Wrench.

The Stock Alternator Pulley is the Black Pulley on TOP and the Black Pulley to the Left (in right photo).
The MCH-208 is the same Diameter as the Stock Pulley.........The MCH-208 has identical Offset as the Stock Pulley.
Actually the MCH-208 is just a tad larger diameter................The Stock Pulley uses a separate thick offset washer.

http://i287.photobucket.com/albums/l...ac31b4ab6b.jpghttp://i287.photobucket.com/albums/l...801ba3feb6.jpg

This Pulley can be installed without removing anything including the Serpentine Belt (except the Original Alternator Pulley).
Look for MCH 208 on Summit Racing MCH-208 or Ebay MCH-208

http://i287.photobucket.com/albums/l...a14de41c4b.jpghttp://i287.photobucket.com/albums/l...95b58bac99.jpg

Oh.....by the way.....I just invented a New Way to install the Serpentine Belt......Remove the Alternator Pulley (takes 1 minute) and position NEW Alternator Pulley inside Serpentine Belt and lift up the Alternator Pulley and Serpentine Belt with Belt Tensioner compressed (Keep Serpentine Belt aligned with Belt Tensioner Pulley). Now just slip the Alternator Pulley onto the shaft (very easy to do and plenty of play) and tighten up the 15/16 inch Alternator Pulley Nut. :D

Lastly......install the Aluminum Alternator Pulley Cap with the three Allen Head Bolts provided with just a little torque as they are threaded into Aluminum.

If you look closely, you will notice also my ALL Aluminum Belt Tensioner Pulley.

http://i287.photobucket.com/albums/l...0157f1027b.jpg

See All Aluminum Alternator Pulley

Re: Finally.....The Correct Size Alternator Pulley
 

How about that! I had to have the back machined for correct offset. Seems you found one with correct offset. Congrats!
http://i658.photobucket.com/albums/u...s539zluqp.jpeg

Re: Finally.....The Correct Size Alternator Pulley
 

Great Minds Think Alike :handshak:

Yes......just checked the offset of the MCH-208 and appears perfect.
It sure ran nice and smooth ;)

Re: Finally.....The Correct Size Alternator Pulley
 

Received my spare 200A alternator yesterday. Pulley may be a tad small with my unscientific measurements...lol I am guessing it is between 60-62mm. If and when it needs replacement, can always swap out the original pulley if needed.

http://i127.photobucket.com/albums/p...018_224233.jpg
http://i127.photobucket.com/albums/p...018_224616.jpg

Re: Finally.....The Correct Size Alternator Pulley
 

Actually you can run an under drive or over drive pulley with the right length serpentine belt. But I am finding 2.75 inch (as you measure on the face of the pulley) is correct diameter and 2-7/8 even a tad better as it opens the tensioner just a tad more. I have some more of the MCH-208 on the way and will provide more photos in original post using my modified 15/16 inch Box Wrench and 5/16 inch Allen Wrench shortly.

Your pulley looks more like 2-3/8 inch diameter on the face of the pulley.

Re: Finally.....The Correct Size Alternator Pulley
 

Thanks for the pulley tip Cliff. I also do have a spare serpentine belt. But hopefully won't have to worry about that soon, as one of the PO's had that replaced back in 2010 along with getting the belt tensioner rebuilt at that time. And its only been 12,000 miles or so that have been accumulated since then. I was lucky to get about 10 pages of service records from the Chevy dealer that did all of the work on the Z.
But you never know, always better to be prepared to an extent, rather than not!!!

Re: Finally.....The Correct Size Alternator Pulley
 

Unless you want to be "cool" with a MCH-208 Pulley.....the secret of changing Alternators is to switch pulleys from existing Alternator to New Alternator when installing Alternator. That way you are sure the EXISTING Serpentine Belt will fit with proper Belt Tensioner Operation.

A Very Easy Job changing these Alternator Pulleys after installation of Alternator using my modified 15/16 inch Box Wrench and 5/16 inch Allen Wrench. You can change these Pulleys AFTER Installation of the Serpentine Belt. Matter of fact........Install the Serpentine Belt as you change Pulleys placing the new alternator pulley inside the Serpentine Belt that has been installed on all the other pulleys. With the Serpentine Belt Tensioner Compressed, lift that New Alternator Pulley inside the Serpentine Belt up on to the Alternator Input Shaft and install the Alternator Pulley Washer and Nut. Tighten the Alternator Pulley Nut and you are DONE.....Release the Serpentine Belt Tensioner.

Re: Finally.....The Correct Size Alternator Pulley
 

Think I'll stay "uncool" on this one, easier to change out the pulley when need it.....How did you modify your 15/16" box wrench? You may have already posted, and I may have missed it......

Re: Finally.....The Correct Size Alternator Pulley
 

On the Box end I took a torch and bent a 90 deg (at the box) and within an inch another 90 deg back.

http://i287.photobucket.com/albums/l...a14de41c4b.jpghttp://i287.photobucket.com/albums/l...95b58bac99.jpg

Re: Finally.....The Correct Size Alternator Pulley
 

These very early Blue-Point offsets I'd think would do quite well for the chore.

http://alloy-artifacts.org/snapon-bl...-tools-p4.html