Hi i have an 1987 toyota supra turbo targa top 5 psd manual that had ben acting up lately. when i received the car it came with about 390,000 miles original on both body and engine and since then it has gone up to 610,000 miles. Everytime i spool the turbo up in the car the car starts to stutter back and forth and black smoke comes out through the exhaust system. Im not sure if this is because i have a blown head-gasket, turbo needs rebuild, air flow is off, etc... The car is burning oil and i know this because my oil levels drop dramatically after turbo has been used over the course of the week. Do i need high milage even though car doesn't have many miles on it? please help. Thanks