K frame Identification

The lower piece with the sway bar on it had a 360 mounted to it. It was originally off a 67 a body, you can tell because of the idler arm. I upgraded the steering so I had to go with the newer-ish style idler arm. The only real difference that I can measure is the passenger pedestal (where the engine mount bolts into) is about 1.5 further outboard than the one, (with the swaybar), was mounted. I am just wondering how to make the one with the better idler work with my 360.
The top K-member looks to be a stock '68-72 A-body piece from what I can see and remember. The bottom one looks like it may have been modified. By swapping in the upper in place of the lower, you'll probably have to get the stock 340 block brackets, or the Schumacher replacement versions.