I just switched from the crate single 4bbl to the Mopar X-ram with holleys during a engine refresh. My engine builder added 1/2" spacers which I swapped for 1/4" and I did a custom air cleaner. All said my fiberglass hood with hemi scoop sits up about 1/2" at the cowl due to the lack of clearance ( rear portion of air cleaner-to-rear roof of scoop). Overall I am happy with the set up. I still have some tuning to do and with a 5 spd the tune is more forgiving.

Ernesto