I put the FBO plate in my Hemi, but with the vac advance hooked up, when you got off the gas after a banzai charge, it sounded like a machine gun as the 2-fours slammed shut, vac shot straight up and over-advanced. The guy at FBO told me that limiting the vac advance to add only 10-12* was the answer. I hooked my timing light up and, at idle, used the allen wrench to set it to 10* additional advance and noted the idle vac reading, this is using non-ported vac, as recommended by FBO. I shut the engine off, removed the cap and used my mity-vac to duplicate the idle vac on the advance can, used a sharpie to mark the arm where it goes out through the slot milled in the dist housing, drilled a 1/16 hole through the mark and put in a spring type roll pin, Problem solved! The pin physically limits the arm from moving further while allowing an additional 10* advance when driving normally. Backyard engineering, but it has worked fine for several years now.