Actually, quite the contrary.
The tightest tolerances in the entire engine.
Which is why there are often problems with them....... since it’s easier to be outside the tolerances when the range of tolerance is so small.
For quiet operation, I’ve seen the best results over the last several years by not using really fast lobe designs, and using the Hylift Johnson/Topline slow bleed lifters(“s” suffix.....A-2011S for the SB Mopar).