I ran variable bleed lifters in the 80's
It's been so long I forgot who made them but they did not make as much noise as the Rhodes (I think they were made by Crane). I was running a hydraulic with duration in the 240's @.050" in a 3200lb 4 speed car.
They were OK; but with todays lobe profiles, I really don't think you need them, especially with durations in the under 220* @ .050"
The 268 is an OK grind, but why not go with something from the XE series if you are looking for an off the shelf cam?
I switched from a 270 magnum to an XE256, pocket ported the heads and was happy with the results till I lost an intake lobe after 40,000 miles. (probably to the reduction in ZDDP levels in motor oil).
I called a little cam company on Georgia, Reed Cams and they custom ground a cam for my application. Even though the specs are very close to the XE256 (within 1 degree @ .050") the truck runs better and gets better economy by roughly 1 mpg.
The price for the custom cam and lifters was about the same as a Comp Cam/lifter set. ($200 delivered)
http://www.reedcams.com/I filled out the vehicle spec sheet,
told em what I wanted to do with it,
Placed the order on a Monday morning,
Got it Thursay afternoon....
http://www.reedcams.com/camform.htm