904's Keep Failing on 67 Motor

540slant6 said
So I have a 67 spec forged crank 318 in my Duster with a 67 spec 904 Auto. However, the motor came from a Sattelite that had a 727. So I changed the flex plate and have now destroyed 2 904's. The first trans broke off the convertor shaft clean at the welds. The second one is now puking fluid out the front and is doing the same thing.

My theory is that the 67 motor crank is only drilled for the larger 727 convertor snout. So the smaller 904 snout is walking in the crank and destroying the 904 sized convertors? Meaning that the 67 crank is drilled larger than the 904 convertor snout. I know that 67 is a weird transition year so any input is greatly appreciated.

I'm at my wits end and running out of money......

Common issue when using a 67 and earlier converter in a newer 318 crankshaft with the larger crank register. A buddy of mine who happens to be a member here and an accomplished machinist built me a spacer that fits over the converter snout. The spacer ID fits over the snout while the OD of the spacer fits the crank register.

In the interest of respecting his identity and privacy I cannot give you his information however he does follow FABO so he may see this thread and offer his assistance.

If not, any machinest with a lathe can fix you up. All he needs is the converter snout OD, the crank register ID and depth along with an explanation from you what your problem is.