Damn you had to remind me back in the late '80s, I bought the neighbors rotted out '72 Skylark GS only for the 455 but also used the TH-400 after learning the short vs long tailshaft was better suited for my app. PO told me it had a BOP 10-bolt 3.90 under there. I let the city and county take it away when I figured I had no use for it at the time. 😢