Got a call from the crank grinder today. They have my 312 crank all ready on the main journals and rod journals but they are concerned about the rear seal area. They are telling me that their crank grinding machine will "grab" the rear seal journal if they use the machine to turn that journal down. They want to use their lathe to turn down the rear main seal journal and then polish the journal to match the 292 crank I left in the shop for them to compare.
I have not heard of doing this, but they have been in business for over 50 years and have an excellent reputation and have done top notch work for me in the past. They believe by turning the rear main seal area down this way they will be able to keep the rear slinger also.
Any of you guys have any words of wisdom on this one? 312 cranks are drying up and I don't want to lose this one
Daniel JessupLancaster, California
aka "The Hot Rod Reverend" 
check out the 1955 Ford Fairlane build at www.hotrodreverend.com