Well after posting on three sites, I think I found out a few things. I was surprised I got no responses from the A12 board. I think those jacks are 33 1/2", though.
Most 70 ebody jacks are the post type but there are exceptions. I have determined that one of my jacks I just picked up in a big parts trade is in fact, either from a 70 Cuda or a 70 Challenger. He had a Cuda since high school and the hook I got with it matched in color with the Cuda part number. I can't help but believe the Challenger uses the same length mast. There is a good informative post on for e bodies only with a mostly accurate chart about jacks. In short, I believe e body jacks are longer than B body jacks. So the 34.5 to 35 seems like an acceptable length. That is the same length and style of jack that I have confirmation that came out of two c bodies I am certain of the origin. Dates are too early but I have found that not all jacks have dates on them.