Before I was going to install headers I just spaced the engine forward 3/4 of an inch. The cap just fit. I also fabbed up a new trans crossmember as I am using a push button 904 from a B body and it had a different trans mount.
Now I will have to move the engine back to use the headers so I will have to modify the firewall/wiper mount.
If I am successful I will post the results.