Seems a little high for that coverage, but not outlandish (to me). I'm not sure what year/model truck you have as that can make a difference.
I pay around $140/mo/vehicle for mine. When I had my Silverado 1500 it was about $110/mo. However, I do have 100/300/100 and $500 deductibles, and one minor parking lot accident, no tickets (lose a signifiant claim free discount).
I'd suggest shopping around.