Josh wrote:
I use a Mallory Hyfire 685. The only reason I use it is for the built it window switch and timing retard for nitrous. The car is no faster with it, it doesn't idle better, and has no other desirable characteristics.

On initial install, I mounted it under the hood and it failed in about 2 weeks. The replacement failed in about 2 weeks, in the same location, under the hood. I moved the third one to the storage compartment behind the passenger seat and haven't had a problem with it in 4 years.