Ford Repair: 390 rear main oil leak, master mechanic, lip seal

Question
I have a 67 390 that we have redone and put into my dads 73 F350 camper special. The engine came out of an old bird I used to own and when we tore it down we found it was not just the run of the mill 390. It looked to be similar to the old PI 390. Anyway, after 30 over, crank turned, flattops, a cam and carb, we have an oil leak that will not go away. The rear main is leaking after trying a lip seal type seal and a rope style seal. A friend of my brothers told him the block is worn out at the rear main. My father was a master mechanic at a ford dealer for 30 years and he just is not buying that the block is worn out. I am having somewhat of a hard time with that idea as well. I do know that the engine has not been hurt, and was not leaking a drop when it was in the bird. I need a new perspective on what might be wrong here. Thanks!
                            Randy
                            Hartland, Mi


Answer
Randy,

I agree with your Dad and you that the block is not worn. My suggestion to you would be to put in a new rubber seal and make sure that it does not get pinched when putting it in. if I can be of further help, please let me know. Good luck.

Ken