One thing to consider is that most of these super fast leaf spring radial cars (like Rhodes') have to be on a flypaper track to run these numbers. I don't mean decent prep, I mean fall down and you can't get back up prep.

Take two cars, equally set up but one on ladder bars and one on leaf springs...now put them on a marginally prepped typical test and tune track. My money is on the ladder bar car.
Dave Dudek has been 9.80s on polyglas GT tires...does that mean everyone slower than 9.80s is a fool for running sticky tires?

Look, I'm not saying Cal-Tracs aren't great...I run them on 2 of my own cars and I've been sorta fast (mid 5s in the 1/8 at 3900 lbs), but the simple truth is that ladder bars are superior. You really think any of these leaf spring guys wouldn't jump ship and weld in ladder bars if their class allowed it?