So, many know I've been putting together my own SOT kit from left over parts. In case any of you kit owners ever need to get a new auto-tensioner here are the part numbers.

It comes with a Dayco 89269
Gates equivalent 38178

Thought I would post for posterity.

 

 

This is good info. My idler pulley/tensioner is starting to make noise and I was looking to replace it. Thanks for posting.

 

No problem. It took me awhile to scour the net. It was actually the Miata forum that helped me out. Just thought I would share the wealth.