67 can be modded to 68-72 if you make a geometry correct accurate jig made off a 68-72 K frame. Pix below are A 67 slant 6 K that using a jig I made to mod it into a V8, and another jig into a 68-72 K frame. There are more slanty Ks than V8 Ks. If you have a rotted or bent V8 K frame and a solid , straight slant 6 K frame, it makes a lot of sense to convert it. The idler arm mount and RH V8 mount for the converted slanty K came from a V8 K that was rotted out in the middle. Motor mount is done. I still need to weld the 68 up idler mount in, and unbolt the jig. Then sandblast and paint it. The jig holes are drilled and welded to steel tubes that accurately locate the bolts so there is no slop in it.