OK, took the day off today to mess with the truck. It's amazing how much work you can get done if you're not at work.
I did the mod to the engine mount adapter plate just like Bob did so I can use the stock compressor and brackets. Only difference is instead of welding an extra plate to my engine stand, I just moved the engine stand back on the frame the same amount as I moved the clamshell mount and everything lined right up. If I have any clearance issues later I will deal with that then. Got the engine and trans in and bolted to the engine mounts. Will need to make a custom crossmember for the 4l80e and once everything is square I will drill new holes for the engine stand on the pass. side. Well, at least it's in. I know I need to paint thr frame, this is just a mock up. Also, with the trans pan level under the truck the oil pan only hangs about 1/2 inch below the crossmember. Shaweet.