the difference is the beak design. I think the 88 is shallower - Vandoren has a picture of the two on their website showing the profiles.
http://www.vandoren.fr/en/clarinetbb.html
then menu on left "Chhose your mpc"
"the only difference between the Traditional and Profile 88 mpcis in the exterior angle of the beak. Therefore, the musician is free to choose the model which wuits his purose in terms of the best playing position. etc ....
