I know quite a bit about them.
Launched in 1980, in every other country but USA it was a GSX as its a 4 valve TSCC motor. (two valves per cyl are GS motors)
A 1700cc 190 bhp conversion is still available for about $5,000. (well in 2006, when I last checked)
Massively overbuilt but still possible to grenade the clutch (plenty of race bits available though, at a price)
300bhp drag race motors were relatively common at one time with surprisingly little modifications for the power output.
Its first of the plain bearing crankshaft Suzuki's. I like them.
saw 1980 Bol D'or when Suzuki won from Honda with modified 750 version that looked an awful lot like the later SACS cooled Gixxer motor.
PJ