I have a good friend who purchased a new leftover 2012 FX4 SuperCab F150 with the 5L V8, 4WD, 6.5' bed in 2013 Vin 1FTFX1EF2CFCxxxxx and it has the towing package. He had it Ziebarted and the bed lined and he has taken meticulous care of it and it only has 12,000 miles on it and he wants to sell it for $26K. He purchased it for $35K. It has P275/65R18 tires. I am interested in purchasing it. However I want to be able to tow my 990 which is 6500 lb with it. The axle ratio on this is the 3.55 according to the door sticker (19) which from the specifications states that it can only tow 7800 lbs. If it had the 3.73 axle ratio it could tow 9400 lbs. Here are my questions:
1. Can the axle ratio be changed? I am guessing that you have to do it both in the front and the back since it is a 4x4 if that is possible.
2. Is there anything else that would need to be done in order to increase its towing capacity?
3. If a change of the axle ratio is all that would need to be done is it best to take it to a dealer or is it possible to do oneself if you have the tools and the where with all to do these types of things?
3. Also one last question what is a typical cost to change out the ring and pinion, again if it is possible?
I have attached the specs for the 2012 F150's and this gives the towing specifications.
Thanks for your help.