Mike, I use the cheapy Pro Comp/Speedmaster aluminum one. I did substitute button head screws for the supplied Allen head cap screws as the button heads better fill the recess for the hole. Also, I cut off the front oil pan sealing lip and used the steel ring from a two piece cover to seal the front of the pan. The aluminum cover just seals flat to that.
Just got off the dyno....takes maybe 10 minutes at most to change cam timing, including a couple sips of coffee. Siliconed the lower bolt hole closed (behind the damper) to make things easier. Also made a Lexan cover for it for some other things we were interested in looking at
. Here's a couple pics:
