Easy fix. See it alot in the Auto cars.
Loosen the motor mounts with car on lift or safely supported...move motor over a hair and retighten.
It's a matter of the engines sitting differently in the cradle bushings. Yeah, some ishy headers are a little more common than others....
, but slamming them solves nothing for anybody.
Just do a little due diligence and almost all of em will/can fit nicely.
Sure there are brands that have a higher success rate than others as well......
GL and let us know how it turns out.
Ivan @ Southwest Speed