Quick Question

The slant six and small block had the same issue. The size of the crank hole changed between 67 and 68. The early hole was smaller, so the late converter and/or flexplate will not fit. It is possible to use a early trans/converter with a late engine, by using an "adapter" ring in the end of the crank, and the late flexplate. But you cannot put the late converter/trans up to the early engine, without a custom made converter (or swapping to the late crank).