Thanks for the added details.
It is possible that it is the best suited pulley for this application, but being suitable for SL65 and SLR McLaren, does not necessarily guarantee that it is bulletproof in all applications. Glad that it is trouble-free on your car, but still I would keep an eye (or ear) on it. Pulleys of this size (often using a 6203 bearing which is rated as low as 12,000 RPM) can run into trouble when they are smaller than 74mm. Your Pulley will be spinning at 17000 RPM as you get to max power, so I hope that 18,000 number is right : ) AND, this is if you are using a stock crank pulley, if some one is running "stacked" they will see over 19,000RPM on this pulley's bearing before reaching max power ...

So, it may seem like I raised the alarm unnecessarily, but this is a 55mm and the 60mm that ASP uses in their pulley kits that they sell through various vendors for this platform (with larger crank pulleys, so they are naturally subject to higher RPMs) RARELY last more than 30,000 miles . When it fails, it always leaves you stranded and occasionally damages the boss of the water pump where it mounts. ...

I never meant to suggest that this is a bad choice, on the contrary, it seems like the best available solution short of having custom pulleys made (like I used to do when I made/sold the Belt wrap kits for this platform before they became too expensive to produce). However, it wouldn't hurt to listen to the pulley every once in a while just to be safe.

This pulley seems like a great deal. I am going to get one or 2 and add them them to the collection. Can you post a link to the bearing spec?

Cheers,
Chris