Slant 6/904 flex plate no longer fits on new motor

Correct, you need the later 68 up flex plate (they are available new), and the adapter bushing. I do have them available. Send me a PM.
It looks like you still have some kind of bushing in the end of the crank. That needs to be removed.
Awesome thank you guys I was about to swap crankshafts from my old motor so glad I won’t have to rebuild My slant for the 3rd time. :p
Correct, you need the later 68 up flex plate (they are available new), and the adapter bushing. I do have them available. Send me a PM.
It looks like you still have some kind of bushing in the end of the crank. That needs to be removed.