The adapter plate could be upside down, I just put one on my car last night, I had an open spacer originally, but it didn't really seem to like it, plus Edelbrock recommends a 4 hole and not an open style. I haven't had a chance to drive it yet, my oil pressure line has developed a leak, have to fix that first. What adapter are you using? I have the Edelbrock 2696 pn, and it definitely is not reversible.