Did these cars ever come with a 5 speed auto?

[CoyoteStarfish]

... Because I think I got one. Or at least my 4HP22 is pretending its a 5-speed.

I can count 5 shift points from a stop OR possibly 4 shift points and a very dramatic torque converter lock-up.

The RPM drop into this mystery 5th gear takes place above 50mph and drops the RPM about 300Rs.

If I stomp on it, it drops back down to 3rd for passing. Then back into fourth and then drops into "5th".

Does this make any sense?

[Fimum Fit]

What you are feeling is the torque converter lock-up taking hold, not a separate gear shift, but a substantial reduction in rpm due to the slippage being eliminated. On some cars and trucks, like my old Ford Aerostar, this actually happens between 3rd and 4th under relatively gentle acceleration, not after the shift to 4th, which can make the shift to 4th rather harsh, but can also save fuel when cruising in low speed limit areas where you don't get into 4th but do have the converter slippage locked out.