Yolk Flange Query

[Monkey Man]

I need a little info on M37/WC yolk Flanges
I have a friend with a WC Dodge that has got the seals replaced but cannot get the yolks to go back in, the leather has been soaked and worked so the seal itself isn't the problem. He fitted newstar seals from VPW so they should be correct but the yolk seems to be striking the metal seal face and he suspects the yolk had been built up at some stage. So, what he needs is the dimensions for a WC flange from the pinion end to the seal end and is an M37 the same dimensions?
Thanks

MM