Gary....hope you don't mind that we've totally hijacked your thread     disclaimer: I wrote this over the course of about 2 hours.....as I kept trying things and searching for part numbers and dimensions......so it's kind of a Train-of-thought post. Bear with me.....it's worth it!!       so, I just went downstairs and looked. the inner seal is definitely different. I don't have an XT6 seal on hand, but I did have a Beck/Arnley 0523586 (front inner, bought for a '92 legacy L, but good for most EJs). That seal was just a hair (probably 2-4 mm) too small in both ID and OD.   so, here's the specs on the XT6 one from rockauto.com: Shaft Size=2.283" Housing Bore=2.992" Outer Diameter=3.001" Width=0.307"   if we can find these same dimensions for the EJ one, we might be able to find a seal from something else that will fit and allow the crossover.   it does mean that EJ axles would work with ER knuckles, but the seal just wouldn't be seated tight against the CV cup.           alright, just found some more info. Beck/Arnley part# 0523586 on the Timken interchange chart is the same as Timken #225673. go back into rockauto with that part #, and it comes up with a few subarus (only listed as FWD.....but if it's an interchange with the B/A part number, it should work for all), and also some Toyotas (corolla, paseo, etc.)......look it up under the toyota application, and you find that same part number under the BCA/National brand.......with dimensions!!!! Shaft Size=2.205" Housing Bore=2.874" Outer Diameter=2.883" Width=0.295"   I was able to reproduce those dimensions on a couple different interchange searches (geo prizm, the toyotas, and a few subarus).           so, after some work with a calculator and tape measure (boy I wish I had a caliper....). those dimensions appear to be almost dead on.     so, for an EJ axle in an ER knuckle. we're looking for a seal with the dimensions: Shaft Size=2.205" Housing Bore=2.992" Outer Diameter=3.001"   and for an ER axle in an EJ knuckle.... Shaft Size=2.283" Housing Bore=2.874" Outer Diameter=2.883"         then I found a Timken "Seal spec guide" http://www.timken.com/zh-cn/products/Documents/SealSpecGuide7533.pdf       for the first conversion....I found a couple that are very close: 2.205 2.992 2.998 0.193 710108 2.205 3.071 3.082 0.295 225678   I think with the width, the 225678 is the way to go.   for the second, I found this one: 2.283 2.874 2.878 0.335 710439 not perfect....but I think that's as close as it's going to get.....     I think in the morning, I'll see if I can get my hands on either of these locally.....