I suspect I can get better then my e bag special air cleaner and just looking for some good ones. with all the marketing hype out there it seems hard to believe what's good. I read the you should have a min of 2" from top of carb to top of filter. I have to run a drop base and with my 3" filter I have 1.5 inches of open filter,maybe a myth I don't know?
Thanks!

Engine masters ran a big ait filter test and the best [performers were the ones that allows as straight a shot into the venturis as possible.

https://www.dailymotion.com/video/x693421

thanks for the link,very interesting results. according to this I should block off my 14"x3" filter and add a filter top for best performance. as I expected the drop base hurts performance but maybe not if you block off the side and add a top filter like a velocity stack? something fun to try I guess....
I've read somewhere that Holley carbs like air entering from the sides more then the top though. Don't know how true that is or if it would even apply to a street car with 500 horse.

Well, a dyno is not an engine compartment. I would think a dual snorkel air cleaner ducted to fresh (cool) air would be best. Something like these

https://tinyurl.com/yagkf9hs

this vid https://www.youtube.com/watch?v=1KyVDUaVz-4 was not that encouraging

I did notice that he had the base mounted incorrect. the humps that were blocking his airflow are there for the Holley float bowls of course and should have been facing front and aft.
anyone have one of these cold air intake systems? please chime in!