Coils are so much nicer going down washboards, they don't tend to skip about even in a solid axle vehicle. The ride in a 80 is night and day over a 60. Why put in an engine to make the vehicle go faster, if the suspension can't keep up? It is like me taking a modern 4T dirt bike engine, and tossing it in a 70's chassis...go from 12" of travel to 4"...makes little sense.How would it overwhelm the suspension?
Drive them back to back, the 80 is like a trail couch, 60 is like a buck board. Zimm knows this...
You can make leafs perform nearly as well as coils, but you have to throw a bunch of money at it. At that point, might as well just change out the whole chassis...the 80 has been well sorted over the years, can buy everything off the shelf suspension-wise.
LS engine swap, 80 chassis, 60 body...the whole package. Power, handling, and the "look". Why half-arse it?