Does anyone know why the 132.5 WB supercab 5.4L truck is rated at 8100lbs towing and the 138.5 WB super crew is rated at 9500 lbs. Is there a frame, shock or spring rate difference? Just trying to do my homework. Would like the shorter wheel base but can live with the 138.5 for the increased towing capacity. I'm looking into the FX-2.
Thanks, Mike

 

There are a lot of variables. From what I understand the tow ratings are not based on what the truck can pull, but how much it can stop in a given distance. So variables such as brake type and size, tranny type, physical weight of tow vehicle, wheel size, tire type, etc. all come into play. Look at the the tow rating charts, you will see a considerable difference just by going from a 17" to a 20" wheel on the exact same truck. The bigger the wheel the lower the rating, I assume because less rolling resistance is harder to stop.
Of the two trucks you mentioned, it would reason that the longer wheelbase super crew would be a lot heavier then the short supercab and therefore have the mass to "whoa" a bigger trailer.

 

The frame is shorter and i'm sure the springs are different. The Supercrew with the 5.5' bed has about the same ratings (tow and GCWR) as the Supercab 6.5' bed which. The 132.5" WB Supercab has the 5.5' bed.

 

I recently purchased a 1988 F-150 XLT lariat with a 302, does anyone know the tow rating for this truck

 

How much can a 20 year old truck safely tow? Seriously, have everything inspected, but I'd be careful towing more than 2000 pounds until I knew more about the condition.

When new with an automatic, it would probably tow 5-6000 pounds. Gear ratio has a big impact on tow ratings too.

 

completely wrong, tow rating are not based how fast the truck can stop the trailer. 1) 'cause if you tow ANYTHING, your trailer should have its own brakes to stop itself. 2) trucks are only designed to stop themselves.
tow ratings are based on engine torque, trans type, rear axle ratio, tire size, and over all weight the truck can get rolling down the road. The more torque the engine produces at lower rpms the easier it will get a trailer rolling, same with transmission gears lower gears multiply the engine torque by what ever the gear ratio is. The rear axle gearing "ratio" also multiplys torque. now here is the big one, the bigger tire diameter you have the less torque that actually reaches the pavement to get you moving, this is why there is a difference between a 17" wheel and a 20" wheel.

 

I believe with these ratios you'll be safe
3.08 = 2250lbs
3.55 = 4000lbs
3.73 = 5500lbs
4.10 = 7000lbs
I wouldn't go with anything over these numbers, 'cause to the best of "my" knowledge the 302 didn't have alot of torque down low. Others may disagree with my numbers, but doing the math those would be considered safe to me depending on gear ratio.