Mal , good to see you still plugging away FWIW i have dynoed my 440 and have found less than 5 rwhp difference aircleaner to no air cleaner ., but i have seen 20/25 rwhp gain with my air box . With a six pack scoop i would never run filter free , see a few motors eat something they shouldnt on drag strips . I run a 14x3 k&n with filter top , with drop base attached to the air box which is heat resistant fibreglass sheet . Maybe a taller filter may help Nearly time for a new season to start
Tex
New best ET 10.259@129.65 . New best MPH 130.32 Finally fitted a solid cam, stepped it up a bit more 3690lbs through the mufflers New World block 3780lbs 10.278@130.80 . Wowser 10.253@130.24 footbraking from 1500rpm Power by Tex's Automotive