i had the "pleasure" of rebuilding several pinto heads after about 10-20k on that vile stuff, if youd have seen what i saw you really wouldnt let it within 100 paces of your engine, let alone run it on the stuff, god knows what is is they use as the lead substitute, iron fillings by the looks of what i see.
okidoki m8 its not going in again then lol
(and the way i drive this car ill probably break the engine soon neway )