A Little More Air
On most big block installations, there is not enough hood clearance for more than a standard 2 inch filter.
Using a 15 inch cast aluminum air cleaner, The air cleaner base was cut with a 1/8" end mill at the inside edge of the filter
allowing the filter mounting surface to be lowered 3/4" using 1/8" aluminum flat stock.
The new assembly was then welded. All welding was on the inside, leaving a very clean look on the outside. On the inside, all welding
was ground smooth for a finished look.
A K&N Round filter PN E-1430 is used. There is enough room on the Holley 850 DP (with no choke linkage) to drop the air cleaner base another 3/4" with some minor throttle lever modification, but
it is difficult to get a K&N filter that is 3/4" taller. K&N does sell a 4" oval air filter, but it's about 1/2" too tall
New Air Cleaner Assembly
Air Cleaner Base and Filter Assy.
Air Cleanrer base and round K&N filter
Further experimentation revealed that increased horsepower could be achieved by adding a 1" 4 hole phenolic carburetor spacer.
To accomidate the spacer and still maintain adequate hood clearance, the air cleaner base mounting ring (.60") was removed and a switch from the K&N E-1430 filter (2.7" tall) to K&N E-1450 (2.5" tall). These changes also required the choke air horn be removed so it would not interfere with air flow, holes and grommets had to be added to the base to
accommodate the float adjusting screws and the throttle lever had to be modified to clear the now lower base.
Ring removed and holes drilled
Auto Trans linkage cut off
Play Doh to check hood clearance