Originally Posted by SHIPCHIEF
I'm trying pieces from a Spectre universal remote air filter.....
It has a cone shaped K&N filter inside.
No point in re-inventing the wheel. Sounds like a 4" dia base x 5" long cone filter. If so, it doesn't provide nearly enough media area to avoid a significant pressure drop. Don Rivera was kind enough to measure a similar filter for me, a K&N RU3120 with the outlet spigot removed. The test assumed 1400 PPH for the 390. Your demand would be a little less, but probably not enough less for a good result. Restriction gets worse when dirty.
The canister was 6" diameter, but otherwise is about what you're trying. Sorry.