I recently worked over the older MP electronic distributor in my friends GTX. With a Lunati Voodoo hydraulic FT,mildly ported 906 heads and a Holley SD with a 750 AFB, it was a bit sluggish on the bottom end. I put the FBO limiting plate and springs in it, and adjusted the vac advance for an additional 10* at idle. The difference was amazing, super sharp on the throttle response and my friend had to relearn how to take off from a light without spinning the tires. If you follow FBO's instructions, you can get your dist squared away and the advantages of having a vacuum advance that works properly will be obvious. My buddy said he picked up a little mpg to boot!