it took me awhile to find a way to mount this without the filter rubbing on the master cylinder or reservoir. i had to add an inch of spacers to the donaldson bracket and kept fighting between it rubbing there or rubbing on the hood. the spacer is powder coated well. clamp was nice. i would not let the filter just sit in the engine bay.

I purchased the filter kit thinking that it would be the first of a series of performance upgrades. The kit is nice and includes everything needed to install, but there are a few things to know before starting. First, you will need either to cut your existing airbox to still retain the battery hold down feature while allowing to 6637 filter to fit under the hood without smashing it, or you will need to purchase the $80 Motorcraft battery tray so that you can completely remove the entire factory airbox; this is something that should be explicitly mentioned under the product description. Second, this open element filter makes a lot of noise. It isn’t loud per se, but after driving for even just 30 minutes, my ears are tired of the drone. There are ways to fix this (sound deadening, building an enclosure, etc) but they do add to the cost and complexity of installing a filter. If drone is bothersome to you, or if you want your wife to ride in the truck for extended periods of time, opt for an intake kit that has an enclosure. All in all, it is a great way to gain some additional airflow at a great cost, but it does require either modification or additional parts to complete the install.

The 6637 filter kit components are of high quality and fit well in my superduty. Delivery was quick.

Was as descripted, and ift perfectly

i am very pleased with the air filter it works good

Easy install great quality. Comes with everything you need. Took maybe 10 minutes to take the old assembly out and install this kit. Sounds great and the retirement is big enough for a Mack truck. Very satisfied

Fits great good quality clamp and pipe and man it makes some beautiful noises.

This 6637 Kit with the Donaldson Blue Filter, is the most straight forward, affordable, quality improvement I have installed to date. The results were instantly noticeable the first time I started the truck and headed up our steep dirt driveway. Throttle response is immediate and increased power is phenomenal. Pulling out onto the highway the increased power literally put us back in our seats. Most importantly there is no more lag and the available power makes the truck feel much safer to drive. I stay with Clay because the true value is not just quality and price, but the service before and after the sale. Clay is the most honest, thoughtful, business man I have ever dealt with, providing top quality products, often times within two days, at prices competitive with everyone else in the industry.

Great kit, i love the fact they included a new clamp. Installation was pretty easy did not have to do any cutting of the old filter box to get it to fit.