I know weird stuff happens when you start messing with different throttle bodies on the E67/E38s, it could be as simple as sitting down and really working on the tune. Gotcha on the air flow, I know some TBSS guys run LS7 throttle bodies on Maggied engines. Not many boosted I6s out there AFAIK, kinda in uncharted waters.

If you can get an 08-09 motor, just swap it. Much easier than swapping cranks. Also, Im in the market for an 06-07 I6 if you wouldnt mind keeping your eye out for one. Probably wont have the $$ to buy one until the end of summer or fall, but another set of eyes makes it easier to source one!