While I am waiting to get the right answer for the crank pulley, I installed a new metal t-stat housing, new thermostat, and new water distribution pipe. There were no leaks, but the metal one looks much tougher than the plastic.

The most difficult part of the job was the back two bolts on the housing. They come off a quarter turn at a time with an 8mm open end wrench. The air intake gets in the way of a socket. Anyway, I used 15 inch zip ties to hold all the hoses out of the way and replaced the short hose between water pipe and new metal housing. Be organized on this so you don't tangle your plug and wires with hoses. Although I would rather have changed several hoses because I have new ones in stock, the current crop is good and I couldn't get to the clamps.

The old parts are fine except for the housing alignment tabs and all the orings looked shot, so fixing this now may have been good.

One change I made to make the housing back bolts easier is to change two of them with the water pipe. saved a quarter inch and made bolt down easy and the extra length on the water pipe doesn't matter