There isn't an o-ring at the thrust washer. A thrust washer is a washer with slip fit to go on the inside of the bearing inner race. It is used as a retainer on the inside of the bearing race to keep the cam from sliding out against the cam plate. Something for it to ride on laterally. I'm not a mechanic or engineer so my .02.

 

Thanks to all who replied. The reason I asked about the o ring is because it was mentioned in the directions for installing the thrust washer and inner race. My understanding is that its purpose is to make sure the thrust washer gets centered properly. Everything seems good with the assembly as it came out of the box, so I am not really concerned just curious.
These are the correct cams for the swap. If I had gone with the Andrews kit which uses roller chains on both sides of the plate, I would have needed 'N' grind conversion cams. The cams I wanted to run were not offered in a conversion style, so I opted to use the Screaming Eagle hybrid kit part #25284-08 which converts both tensioners to hydraulic, but maintains the OEM silent chain on the inboard side of the plate enabling you to use any grind cam that is made for a TC88, including stock if you would so choose.

 

You learn something new everyday......

I think its a good idea to offer a conversion kit like this.

I only knew of the N series cams where you use all 2007 up cam plate and chains.

Good to know this is out there.