I've been watching this thread because I am about to do a coil over front end on my 70 RR, not because of clearance or anything else really, its more because I want to. I already have 2 E bodies with T bar suspension and this RR is pretty much a freak already so I figured "why not". Yes, in the end it will probably cost me more to go this route than stick with stock suspension but to be honest, I don't care. I am not going to a tubular K frame merely because I don't want to, I want to make a front end using the stock K frame and see how it goes. For anyone reading this wondering why or thinking about how much work this will be, my RR already has a tilt front end, snout bars, etc. so it is already hacked up.
In researching this effort, I talked to Hemi Denny (HDK) and he informed me that the #1 issue in this conversion is shock length or better said the lack of potential shock length using the stock shock tower position. His conversion moves the upper and lower mounting points in order to get a usable shock length in the car, in my case this isn't an issue as I can move the upper mount without issue. I am going to be using tubular LCAs and UCAs on this. The trick is to build a positioning system for the LCA since you lose the T bar; HDK has a bracket that takes the place of the T bar and supports the back of the LCA.
For the record I think the stock Mopar suspension is fine, works well and can be made to perform as good as anything else, but since I already have a freak and several other cars, this is my chance to experiment, not to mention I am going to be running a 426 Hemi and I am sure the space provided by not having the T bars will be handy.
