yeah.. looks to be underdriven and overdriven. Depends on your rear tire/gear, amperage requirements(boom boom stereos absolutely HATE underdrive pulleys) and how hard you drive the car. Personally, I think most people get by just fine with regular ratio setups and I'm not sure why they have to try and reinvent the wheel there by only giving you the option of one or the other. Also keep in mind that some alternators don't like to idle at lower than designed speeds for extended periods. Leads to repeated battery drain(reduces lifespan) and voltage fluctuations(dimming headlights when accessories are used for example). I always prefer underdrive versions because I typically drive all my stuff like I stole it most of the time.. but I and others I know have also had issues in rush hour traffic too.
I somewhat recently updated to a 130 amp early 90's Mustang alternator and used a 289 HIPO/Boss 302 single v-belt alternator pulley, which was somewhat of an underdrive compared to the original. There is a high wattage amp installed with a headlight relay setup. Luckily, so far, it has not had any under charging issues. However, I will soon be upgrading to a Taurus electric fan as well.
You could just remove the aluminum' bracket that goes between the alt spacer and head,bolt the alt directly to the head. It should lineup with the pulleys on the crank and waterpump then. I did that to my 70 years ago and it worked.
Hey Will: It's looking good under the hood ! First time I've seen this . Looking forward to you're coming over to our shop. Cometized (Chip)
Thanks chip! Yeah it's been a lot of work.... But I am looking forward to coming up there! Just need to figure out a stalling problem and it'll be good to go anywhere!