HEI style distributor cap
you might mean Davis Unified Ignition (D.U.I.) at
www.performancedistributors.com
I bought one to put on my 318 thats not in the car yet. Took the distributor out of the 273 the other night to see if it would fit and i am very nervous about it, it is BIG. I know that i will have to a bolt that the wiper motor mounts onto, hopefully nothing else will be in the way...
Anybody else have one of these?