Thers no quick fix for a worn out engine. At 146K your pushing the worn out envelope. You can clean it with some "not recommended" trick or additive, but your engine is tired, and needs an overhaul. You will only prolong the inevitable, possibly doing more damage in the process. I wouldnt try any of the gimmicky quick fixes. drive it like it is until you can overhaul it. You can buy 302 short blocks anywhere very cheap. do it once, do it right. save the mystery oils for GM drivers.
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1993 GT/AOD
'93 Mustang GT