Guys have been real fast on Cal-Tracs and they work good for sure, but a ladder bar/coilover setup will be more consistent. Like when I hear people talking about the 3 second 1/8 mile passes on drag radials like it happens all the time...that only happens at radial events w/ CRAZY GOOD track prep.
Or Ron Rhodes' Camaro going 4.30s on leaf springs and a 275 tire.
Like my own car, there are some real fast passes mixed in w/ a bunch of aborted runs due to traction problems.

Unless you have class rules or just don't want to use anything other than stock style suspension, there's no reason NOT to go to ladder bars or a 4 link. Just depends on what you're gonna do w/ the car.
My point is I don't think there's a leaf spring car out there that wouldn't go faster or be more consistent w/ ladder bars under it.

I seriously doubt this applies to the OP and his car. Sorry for straying off the topic.