some coils are variable rate coils, some are not, some are differnt spring rates in different sections of coils. easy way to tell? not really, but for our uses, they are probably not variable rate coils. variable rate coils means that within one coil loop, to compress 1 inch, it takes so much weight, and to compress it another inch, it takes twice as much weight. obviously i'm not useing numbers, just an example.
i highly doubt that rustys springs are variable rate in any way, usually that used in performace aplications where as you take a corner it gets harder to fully compress the spring.
off-road, as in where you are getting articulation, it's not harder to compress the spring past a certain point.
long story short, cut 'em.
