I'm considering buying a '65 396 but want to know if the asking price of $800 is reasonable. its been bored .060 and then sat for many years. As a result, a small amount of surface rust has developed, which will need another 0.010 to clean. Boring 0.070 over might sound risky, but i had it sonic tested and the walls are the thickest i've ever seen (over 0.250 on all cylinders). Worth it?