I got a 02 big Ford Pk

[FarmboyBill]

Its got both leif and round springs in the back. how can I tell if its a heavy hauler or not. Its got around 3 or 4 different leads for hauling trailers and hooking up to the lights on it. For what thats worth. Its an auto. Dont know size of engine. 8

[Jpchar]

Not enough information. Is it a F150, F250, or F350? Look on the drivers door or door frame for the tag which has the GVWR. It may also have the GCWR. The numbers printed after those will tell you what the carrying and towing capacity of the truck is.

[FarmboyBill]

It has
GVWR, 6250lbs
GAWR, 2950lbs
Ford F 150 XLT

[crispin]

Originally Posted by FarmboyBill

It has
GVWR, 6250lbs
GAWR, 2950lbs
Ford F 150 XLT

It is not a 'heavy hauler' a F150 is a 1/2 ton truck with a weak frame and undersized brakes and axles. It is not for hauling big loads.

[Jpchar]

If you have a hitch on it you can occasionally pull a 5,000 lb. trailer. If you are looking to pull trailers for pay, you will need at least an F250(3/4 ton) and an F350(1 ton) would be better.

[zant]

If it has a 5.4-be very careful changing spark plugs-have heard horror stories-never knew changing plugs was so difficult

[unioncreek]

Don't let them scar you. I've hauled a ton of hay on a F150 without any problems and did it all the time.
Sparkplug removal can be a problem on engines with aluminum heads. When you attempt this I would spray PB Blaster or some sort of lube on the sparkplug bases and then start the engine and get it warm. If you have trouble getting the plugs out, but can turn them a little keep applying lube. When you replace the new sparkplugs put anti-seize on the threads that will solve the problem.

As far as pulling a trailer you can easily pull what it is rated for in the book. I don't remember if it's 10K or not, that is trailer and load weight together.

Bobg