I recently installed a rear main seal in a 312 I had on the stand. It was installed without removing the crankshaft similar to doing it in the car. The engine was installed in the car and it leaks really bad; either a bad job, bad seal surface, or bad seal, and leaks so much it has to be replaced again. The seal came from my favorite T-Bird supplier and was black. I read that  the Best Gasket 312 rear main seal is red or orange. I plan to do the engine in car (57 T-Bird) seal replacement. I came across the following article in Gil's Garage of the CTCI website which references another article written by Ted:

"Ted Eaton has written a great article regarding installing the neoprene rear seal. (found in Gil’s Garage). His article also covers other oil leaks associated with the 292/312 Y block engine. Ted finds that as a general rule if his installation instructions are followed the early made for 312 engine neoprene seal featured in his article holds well if the crankshaft seal surface is polished. If not it will hold for a while then usually leaks before 3500 miles. It may leak sooner if the crank shaft seal surface is not perfect.

He believes as I and others believe that the early seal material may be too soft allowing the seal to wear. It has been found that a USA made modified Chrysler seal researched, developed and sold by Fordcraft, works equally well in the 312 engine and it is not as sensitive to crankshaft seal surface irregularities. I have used this seal for several years with very good results. It can be ordered from Fordcraft 972-423-4636 and many other Thunderbird parts dealers."

My question is, since I didn't thoroughly check the condition of the seal surface (although I remember it as OK) before, would I be better off getting the Fordcraft seal over the Best gasket?