If you like MFD's, either find a used set or swap guitars, whatever ends up cheaper and easier. G&L necks vary, so if you like your neck, I'd suggest keeping the guitar.
I have an old SC-3 (1988) in the closet, with a neck that is just too small for me to be comfortable with and MFD's. As I recall, the pickups are nice and aggressive, but did not have the magical "juicy" sound that I tend to like in tele and strat pickups these days.
(I have also owned an ASAT Signature--which is like a Special, and an ASAT Classic, and I did not like the Classic pickups at all, went to tele pickups. I spent a number of years on the Guitars by Leo page as well.)
There is a specific character to MFD's that I find in things like Harmonic Designs Vintage Plus pickups (also with ceramic magnets underneath the pickup) and Bardens (which I don't like as they are too hot and sizzly). Even current MIM tele pickups are made using this construction.
If you want hotter pickups in the Legacy, consider that there are a lot of other choices. Something like a set of HD Vintage Plus's might really work well for you. I also like Rio Grande pickups a LOT.
Also, I have found that MFD's vary from year to year and set to set...kind of like Fender pickups from the old days.
Just some input for ya,