I have an 82 4x4 SR5 22R engine and need to replace the cylinder head. A company on eBay says that I need to determine if the intake has 15 versus 20 bolts in order to buy the correct head. I can't count the bolts w/o taking apart the carb, etc. Is there anyway I can know which head to buy using the engine number? or, is there another way to know this?