I have the option to buy a 91 or 92 SC don't recall which year but it has problems. After blowing a head gasket it was driven about 20 miles and when it overheated it would get shut off. Before these problems it was a mid 14 second car but now after it was fixed there is a massive vac leak and now its shooting smoke out the tail pipes. I drove it about 20 miles and it was smoking really bad and wanting to die all the time. When the car goes over 2kish rpm it will run decent but below it runs like crap and sounds like PUB-PUB-PUB-PUB-PUB-PUB really loud. It has a low restriction exhaust with shorties on it. Any ideas on whats wrong with it and if all else fails could I part it out for more than $500? Would it be possible for anyone to help me take a look at it to help figure out whats wrong with it?