trans slipping....

[crotchrocketony]

hey guys got a tranny issue. i have a 92 svx with 87k. ive had the tranny once and replaced brake band, and revese clutch pack/drum. result of 2 much fun in the snow. everything else looked like new ive put 7k on since then. last night i was on a road trip and it stared to flare shift. i also noticed highway speeds my rpms were high.....as the trip went on they got higher. i checked the tranny fluid......good. i tried switching from drive to 3rd with the same result, but in 2nd there was no slipping......i finished my trip in 2nd gear. any ideas of whats wrong?!?!? and also how do i tell if my car has a legacy tranny swap in it? when ordering a trans fiter advance auto they first gave me a svx filter...didnt fit but a legacy one did