The 16 tooth is what I was looking for and the Zeppin racing list this part for MRX4, Evolva 05,M3.
It is this kind of listing that makes me wonder about the Kyosho pulleys.
Not to mention the fact they are $6 a set versus Mugen at $22.
However I was wanting to run the aluminum pulleys but my usual supplier is out of stock in the 16.
The Zeppinn pulley on Ebay is about the same price as the Titan so maybe I will get one of those.
Would still be interested in the Kyosho fit I think I will find someone with a Kyosho at the nest race and check it out.