I changed my plugs and wires installed a cowl snorkel that is 3" diameter to the stock airbox so I can use stock airfilters. I am getting about 11 mpg and would like to know if an aftermarket OEM style airfilter would boost my mpgs enough to make it worth it?

I have been looking at this Spectre Performance 883901 hpR Replacement Air Filter Element it is $19.99 on amazon. Or a K&N for $45.

It is a 92 with the 4.0 HO running 33X12.50 and 6" lift
Any thoughts?

 

Stock air filter, can be had for about $5 or so, best one in my opinion

 

I would agree. i dont think they are restrictive enough to change MPG/HP when using the stock box.

 

I got a Fram Air Filter...cost me about $6.50

Just change it every 10k miles.