Yeah if the Holley mounts move things forward then it wouldn't be hard at all, the crossmember hoop should be plenty big enough to clear the transmission. I'd have to look, the only possible snag might be a connector or output for one of the sensors lining up with the crossmember. But that should be easy enough to deal with. You'd just have to figure out how to move the transmission mount, but that shouldn't be that hard.
Now, if it moved the engine back it would be a problem, the hoop probably wouldn't clear the transmission