I'll venture a guess that a +/- 2" height change won't create problems, or a maximum 2" change in track width at the tire centerline (1" per side) will also be within reason. Going beyond these limits without a total redesign of the suspension geometry is asking for trouble in a big way. The radical lowering we do on roundtrack cars is accomplished by completely refabricating the frame, with the proper, computer-generated suspension and steering angles built in. One of the popular IFS swaps on the older stovebolt trucks is the F_rd Pinto system, which, in my opinion, is deadly dangerous. It's seriously overloaded for the vehicle, and drops the front end about 4" or so. A rehab of the original suspension and steering, with modern materials such as polyurethane bushings, improved-design tie rod ends, drag link, etc., probably will result in a safe, reliable street machine, with better handling than the original system. Going radical for the sake of appearance alone is not my cup of tea, but if someone wants to do it, it's his business. Just don't offer me a ride.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
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