I have one on my 350 1991 Formula. It's one those things that is supposed to give you an EXTRA 5 hp. Yeah right. If I really believed ALL the claims for every item that I bolted onto my engine I should have 538 hp by now!

The car runs fine, no overheating or charging issues, but I would have to assume that you should have a GOOD battery to start off with, and not plan to have six 500 amp speakers and your A/C going full blast in a 2 hour traffic jam.