I bet if you cough or take a poop it hurts worse. Sounds like a lumbar disc issue, but making an "e" diagnosis is tough. I should be in the office tomorrow afternoon, unless the wife goes into labor tonight.
For 20hp the price of head seems a little steep to me. I am leaning more toward the blower set up. I want to retain driveability, and looking for refills for the spray is a real hassle up here.