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Headgaskets start going when people pump too much boost into their motors 10+ psi, on a hi comp turbo converted motor with no aftermarket ecu for tuning, get an aftermarket ecu, and you should be safe, im currently converting mine to turbo so it will be hi comp with a hi flowed turbo pumping 10psi, hidden front mount and 3" exhaust.
But headgaskets are a problem of hi comp turbo conversion