1970 Road Runner

I'm looking into buying a 1970 Road Runner but no very little to nothing of these cars. I'm into older Packards but like this car and am seriously thinking of buying it. The seller says it's a true V-code car but has as a short block from 1969 440 with a purple cam and deep pan. He's asking $31K. He says even the carbs are the correct ones and I'll try to post engine and exterior pics. Thanks for your help.