To be upfront, I originally had my eyes set on a 17% Alta pulley, only because I like the Alta tensioner stop design and I intended to purchase them together. However, the Alta is either backordered or discontinued, so I looked elsewhere.

I went with Way Motor Works because it's $30 less for basically the same part. I also had a good experience with a previous order. I chose the 17% because my MCS is a daily driver and I don't ever plan to track it. The pulley was shipped quickly via USPS and the rental Craven puller arrived separately from the previous customer.

Installation
The instructions on the website are good and there are plenty of writeups already, so I won't go into that. As far as tools, instead of allen wrenches, I suggest getting a proper allen socket (in my case, 4mm) to install the pulley screws. Also, if you don't want to do the job twice, don't forget the (blue) loctite!

A floor jack is also required to lift the engine; Costco has a 3.5t low-profile jack (Arcan XL35R) for ~$100 which is sold by Amazon / Northern Tool for ~$180 after shipping. It weighs close to 100 lbs and will probably outlive me. Jack stands were obtained from Harbor Freight for $30. I also purchased a belt tensioner tool on ebay for $65 shipped. You can make do without, but it was definitely easy with.

Last, the Craven puller needs maybe a 20mm wrench to hold it while you crank the extractor screw. I didn't have one handy, so I used a large pair of vise grips. Anti-seize is your friend; you'll need a generous amount for the screw.

Driving impressions
Wow, you can really feel the extra power, especially down low! 50-70 is also improved too. To top it off, my MPG has gone up, from 30.5 to 31.7. Perhaps it was the weather? It definitely wasn't the gas or commute. I'm just glad it didn't go down with the way I've been driving.

The blower whine is also more prominent, which was kinda surprising. It's not obtrusive, but it's definitely louder than before at all RPMs. I haven't had any misfires or codes, but I plan to install new plugs this weekend anyway (Brisk DOR14LGS-T... one range colder).

In conclusion, great mod, easy to do (it took me 3 hours, which included jacking up the engine twice to apply the forgotten loctite), and with gas prices where they are, it should pay for itself eventually (ymmv).

PS... On the Alta tensioner stop, I've read about rattling issues, so I just double-wrapped each arm in duct tape. No rattles on mine.

 

Nice! I have been on the fence for some time over a 15% vs. 17% pulley. I am going with the 15%, but that is because I am a worrier. Love reading posts like this!