I checked the base and it sits steady on a table. It was also marked by the seller as a 440 baseplate. I was hoping that it was the wrong part thus fixing the problem. The lid was marked by the seller as a 383 lid though... are there any differences in lid heights? I never knew there was any height difference for a 383 and 440 air grabber, so it never occurred to me that the lid or base could be the problem. The engine in the car is a mild build and seems to like the performer that is currently on her, is there a noticeable performance difference between the m1 dual plane or CH4B and the performer thats currently on her? I would be seriously considering the M1 if it is the factory height as it should definitely fix the problem?? The hood will close with just the baseplate on but once you add the filter and lid,a definite no go. So I believe I need maybe an inch or lil more clearance because the filter doesn't sit very high. I again wish to thank everyone who is sharing their opinions and knowledge.