I'm assuming you're referring to a fuel injected engine and the little "hump" near the fuel selector where the boost pump is. I concur with the other post that you absolutely want a filter. Van's sells a kit with an electric boost pump, filter, mounting plate and cover that's made to fit there. Don't spend a lot of time trying to reinvent the wheel or over-think it...Van's has gotten this stuff down after a few thousand planes.