What is a good 5/6 speed Transmission that will fit onto a 302 Ford V8?

I have a 1970 Ford Torino 500 and my C4 trans is failing. I'm kind of tired of the 3 speed, so I'd like to upgrade to a 5 or 6 speed to get better gas mileage at higher speeds, plus to go faster in general. I don't really mind if it's automatic or manual, but my car right now is set up for automatic.

A multi-speed automatic? That's a toughie, as both the AOD (a four-speed upgrade of the C4 Dual-Range) and E4OD (a four-speed upgrade of the C6 Dual-Range) require some computerization to control the overdrive and the torque-converter clutch.

If memory serves me correctly, the Torino had a stick-shift, most likely a Borg-Warner T-10 with a 10.5" Long Machine and Tool three-finger clutch, as standard equipment; some companies manufacture reproductions of the necessary clutch release rods, cross shaft and bearings, and release fork and bearing. Richmond Gear has both a five- and a six-speed available as upgrades, with a Long Machine and Tool external shifter included; be advised that the Richmond requires a shorter propshaft than the T-10. Concerning the pedal and clutch-linkage installation, the brake arm uses a narrower pedal than its automatic counterpart, and the clutch arm and pivot shaft replace the pivot shaft used with the automatic. Mac's Auto Parts sells a modern reproduction of the FoMoCo P/N B7AZ-2471-B service bushing for the clutch and brake pedals. Lakewood Machine and Tool, a division of Mr. Gasket Company, manufactures a hydroformed-steel conversion bellhousing to SFI specifications (as the 302 Windsor still occasionally sees sanctioned motorsports).