Ive used either on my truck before, you have to be very carefull, which is why its not recomended, but it runs smoother on either then diesel.
I wouldnt recomend it tho, but make sure you change filters, put atlest 4-5 gallons in the tank, and see if your tach moves when your cranking, if not cps. But its going to take alot of cranking.