I'd probably want some where from 4.5-5 its mostly a race car.. but will see some street duty.. the exhaust is dumps out the passenger fender at the bottom behind the tire.. so exhaust isn't a problem.
That will look cool that low...I could only get to 5.5" from my torsion bar cross member to the pavement and feel comfortable and 5.0" to my HDK cross bar, of course my headers ARE my limiting factor to going lower. They are even with the Torsion bar cross member but I would have to have raised the floor pan to get them higher.