66 GMC Suburban questions

[SBTork]

I have a friend that is looking at possibly buying a '66 GMC Suburban. It has the 305 V6, manual transmission(unsure which), and a heavy duty suspension set-up. Nothing special, just 2wd heavy duty stock stuff. Im curious, what are the suspension conversions to get coil front and a modern rear end in it? Does it already have coil front? Can a '73-'91 2wd frame be used? Has anyone done this before? Can the front crossmember and suspension parts from a '73-'91 be bolted directly to the stock '66 frame?
As im sure all of you can tell, I do not know much about the mid-60's truck, suspension wise, but want to learn. Thanks in advance for any info.