i need an after market air filter for my 6.9, but i can only find replacement filters that fit in the stock air box. anyone have a part # for a good air filter/intake? thanks any help would be nice

 

Grab a spectra 14" from local parts store and a air filter spacer from mr. Gasket ..... use at least 2" tall spacer and buy a 14"X6" high flow .... like a K&N .... or ur favorite after market choice ........ then after the Y in the exhaust go up to 4"minimum exhaust ....... it will flow like mad ..... I have a dynomax diesel power muffler ..... but any good open ot cham ered muffler for a diesel will be much better than what's most likely there now .....

 

I built one, for my 7.3, out if black 4" PVC abs pipe like you would use for sewer system in your house with a K&N open element 5" opening air filter. Also near the the pipe at lowes was a rubber adapter for going from 5" steel pipe to 4" abs with some giant hose clamps. Just had to break the throttle cable bracket lose to tuck the rubber adapter in so it had a better bite on the intake.