More knowledgable people here will correct me, but from what I know, the
only difference between a 172-R and a 172-SP, besides the leather seats,
is the prop on the SP, running at a slightly higher speed.This produces
a significant performance difference between the two.

Is it possible therefore to "upgrade" a 172R to SP performance?
I am not referring to some aftermarket cruise prop, and I am only
interested in approved modifications (Cessna approved or STC'd).

Thanks in advance,

G Faris