Tires: Tires, heavy loads, firewood

Question
I have a 1992 GMC C1500, 4.3L with 330,000 miles. I can not read the vehicle placard.  The truck is used for landscaping and tree removal; carries heavy loads of firewood. I need to get tires and don't know size or if it needs P with XL rating or LT.  It has always had mis-matched used tires on it so I can't use them to determine size. I've put 120,000 miles on it since I've owned it and know it probably won't go too much longer.

Answer
Linda,

 Your truck came equipped with either P225/75R15 or P235/75R15.  I would recomend that you use either P235/75R15XL or LT235/75R15 for their extra load carrying capacities.  The XL will be the less expensive of the two taking into account the mileage on the truck.