97modifiedmustangGT

I found one of these on cragslist and on the ad it says it works will piggyback underdrive pulleys. So I did some research and haven't found anything that specifically says that it works with piggybacks. does anyone know exactly? Would I benefit to pick one of these up and just put the stock pulleys back on and adjust timing?

Chopper

I don't see why the timing adjuster won't work with piggybacks but I'll bet you can't bolt the old harmonic balancer to the U/D pulley and use the timing adjuster.

I have a Steeda timing adjuster and it works very well.I picked up a couple of MPG but I don't know about HP since I didn't do a before and after run.That being said,I would have went a different route such as a handheld tuner that adjusts timing from idle to redline instead of the fixed adjuster.There wasn't anything available at the time that I know of so the fixed adjuster it was.Now one of the popular tuners (SCT or Diablo) has this capability I think???
The handhelds also have many more features than just adjusting timing so I believe i would have saved money in the long run by buying a tuner.
Anderson Ford Motorsports has a tuner package that looks good but it's expensive.