The 14" "Corvette style open element" air cleaner (aftermarket version) has a drop base that should work. The factory OEM base that was originally used drops the air cleaner element 1" lower than the aftermarket one. It's contoured around the 3310 Holley that was on the Corvettes and Z/28s that came with that air cleaner. So it might be a little low for your valve covers.
The aftermarket versions have about a 1/2" vertical "riser" section before the "drop base" starts, so that could be a little added insurance if it's needed.
For a historical and detailed pictorial listing of Chrysler air cleaners, on the
www.jholst.net front page, click "Resources" and that'll bring up a long list of links. Near the bottom of that list is one for "Air Cleaners", which is a link to a Nick's Garage page on such. Air cleaners and the filters that fit them, from the later 1950s to middle 1970s.
The Air Grabber is for the B-body people who need them. Only real benefit would be cooler air, not more volume of filtered air.
Be sure to use a SHORT air cleaner stud!
Sleepers are fine, but you can't have a rumbling exhaust if you really want a sleeper vehicle! Don't want to attract unwanted attention.
Don't worry about 6000rpm power, but 3500rpm torque. So a lesser intake might work best if it allows a stock air cleaner to work on the motor.
TIP -- Use the air cleaner base from the Road Runner open element air cleaner, with the normal C-body air cleaner top. Should be better flow as there's more room between the bottom of the upper air cleaner and the edge of the base than the orig Road Runner air cleaner had! Only those with sharp eyes will see the lack of the base mating with the top of the stock air cleaner! Same diameter filter element as the normal C-body filter, too.
A "hot rod" that sounds like a hot rod isn't a sleeper.
CBODY67