Yeah it's the same as the 400 and I do see a little pump out on the seal. I was hoping not to have to split the cases. I am actually restoring the bike and getting ready to put the engine back into the bike after doing top end, clutch and oil pump rebuild. Not 100% sure the seal is even leaky, just replacing everything as this engine hasn't ran in 40 years. Maybe I will just chance this one item, all the rest of the rubber parts I have seen I have replaced.
Thanks, Bob