With mine, I cut the flange off of the MAF and attached the cone to the filter that way. It doesnt work on the filters made for the air box, but anything with a rubber end will work.
I got a scrap piece of 3/8 inch thick pvc plastic material. Used the stock maf as a template and made an adapter. Attach a short piece of three inch pvc pipe to the adapter.
I wanted to be able to return back to the stock setup on the maf and this method allowed that option.
The rest of the setup can be made up with fernco rubber parts and 3 inch pvc pipe.
A K&N FO35A4 cone filter just fits the 3 inch pvc pipe.
Holcomb Motorsports sells MAF adapters in either plastic or aluminum...$24.99 for either also sizes 60-90 mm.I personally found one on Ebay for 10 bucks.It was actually made for a Lightning or Cobra MAF so I had to elongate the holes a little to make it fit.