In an attempt to dispel some misinformation...
There are actually three separate Max Trailer Tow Packages per the 2011 F-150 Order Guide (published 09/03/10). However, the differences between them are pretty much limited to the mirrors themselves. (Package 60C is only available on Lariat, King Ranch, and Platinum, and those already have the SelectShift transmission.)
This Order Guide may be slanted towards the US markets. Hence, some differences may be seen in other markets.
MAX TRAILER TOW PACKAGE – MANUAL MIRROR (60M)
Availability:- Optional on XL Regular and SuperCab
Not Available with:- 126" wheelbase
- Power Equipment Group (85A)
- Max Trailer Tow Package (60P)
Requires:- 3.5L EcoBoost™ Engine (99T)
- 3.73 LS rear-axle ratio
- Heavy-Duty Payload Pkg. (627)
- XL requires Fog Lamps (595) with XL Décor Group (86D)
Includes:- Upgraded rear bumper
- Class IV trailer hitch receiver
- 7-pin wiring harness
- Upgraded radiator
- Auxiliary transmission oil cooler
- Trailer Brake Control
- SelectShift Transmission
- Side mirrors, black manual telescoping trailer tow w/manual glass
MAX TRAILER TOW PACKAGE – POWER MIRROR (60P)
Availability:- Optional on XL Regular and SuperCab, XLT and FX2/FX4
Not Available with:- 126" wheelbase
- Max Trailer Tow Package (60M)
- XLT SuperCab 145" wheelbase with P235/75R17 BSW A/T (T7B), L245/75R17E BSW A/T (T7E) or P255/65R17 OWL A/S (T73)
- XLT SuperCrew with P255/65R17 OWL A/S (T73) or L245/75R17E BSW A/T (T7E)
Requires:- 3.5L EcoBoost™ Engine (99T)
- 3.73 LS rear-axle ratio (XL, XLT and FX2)
- 3.73 electronic-locking differential axle (XLT w/Off-Road Pkg. – 55A and FX4)
- XL requires Fog Lamps (595), XL Décor Group (86D) and Power Equipment Group (85A)
- XL and XLT Regular Cab requires Heavy-Duty Payload Pkg. (627)
Includes:- Upgraded rear bumper
- Class IV trailer hitch receiver
- 7-pin wiring harness
- Upgraded radiator
- Auxiliary transmission oil cooler
- Trailer Brake Control
- SelectShift Transmission
- Side Mirrors, black manual telescoping trailer tow w/power glass (includes heat, turn signal & puddle lamps)
- Memory feature included on side mirrors when order with FX Luxury Package (55F)
MAX TRAILER TOW PACKAGE – POWER, CHROME MIRROR (60C)
Availability:- Optional on Lariat, King Ranch® and Platinum
Requires:- 3.5L EcoBoost™ Engine (99T) or 6.2L V8 (996)
- 6.2L V8 on Lariat and Platinum also requires SuperCrew 145" WB
- 3.73 LS rear-axle ratio
- 3.73 electronic-locking differential axle (Lariat or King Ranch® w/Off-Road Pkg. – 55A)
Includes:- Upgraded rear bumper
- Class IV trailer hitch receiver
- 7-pin wiring harness
- Upgraded radiator
- Auxiliary transmission oil cooler
- Trailer Brake Control
- Side Mirrors, Manual Telescoping Trailer Tow w/Power Glass (includes heat, memory, turn signal & puddle lamps & Chrome Skull Caps)
Incidentally, a class IV trailer hitch is rated for 12,000lbs with a 1,200lbs tongue weight.