Hello, I have a 1967 skylark 300 CI engine that is shot, , cam snapped and rod went thru the side of block/oil pan. I have it out at a local shop, having a hard time finding a replacement I would like to replace with the 350 because, or bigger if trans matches up . I think it would be easier down the road to get parts. What can I use as a rebuild to replace with out doing any mods or transmission changes. Really appreciate any constructive feed back. Thank you, Rob.