273 4BBL Throttle Linkage

I don't recall what was first year for the throttle pressure arm long slot ( free throttle return ) or what year the bell crank moved from mounted on back of head to mounted on the intake.
If I didn't have the later model improved design V8-4brl stuff, I think I would buy all that first.
Any aftermarket 4brl placed where a 70 up OEM 4 brl was, is surely a lot simpler.