Help finding Input Shaft Bearing for 3 speed

[dznucks]

I have a three speed transmission that I believe is a Muncie. I just replaced my clutch assembly, pilot bushing, and input shaft bearing. I took the old input shaft bearing to a reputable, local tranny shop to ensure that I got the right bearing. They gave me a N307LOE bearing. I noticed the bearing was just a bit shorter (~.040") than the original and the guy at the shop told me that wouldn't make any difference.

Now the tranny has been popping out of third gear and i can feel some play in the transmission while driving. I am assuming that this .040" width difference is causing the problem.

The original bearing has the following dimensions.....ID 1.378" (35mm), OD 3.152" (80mm), and a width of .709" (18mm). The new bearing has the same ID and OD, but the width is .669".

Can someone tell me how to find the correct bearing?