i speak from personal experience: the 5sfe and 3sge clutches are identical.
i know this because i have a 3sge in my aw11 and i am using a 5sfe clutch kit.
even the flywheels are the same, UNLESS you get an 86 or 87 3sge, which uses 6 bolts to connect to the crank, whereas the 88 and 89 uses 8 bolts to connect to the crank - which is the same as the 5sfe. the flywheels are the same diameter as well.
if you wish to check for yourself, i fully encourage you to check the following website:
http://www.exedyusa.com/
compare the 88 or 89 Celica GTS to the 90-95 Mr2 non-turbo.
as 'MrTurrari' pointed out, the 3sgte clutch (and flywheel) are NOT the same as the 3sge/5sfe - the 3sgte being considerably larger flywheel, and the 3sge clutch pressure plate does not match up to the dowel pins on the flywheel.
i know this because i bought, what i thought was, a 3sge flywheel and clutch. clutch did not fit. bought another clutch, thinking i got the wrong one. still did not fit with the 2nd clutch. got the correct flywheel and both clutch kits fit.