How to Install a 6637 Intake on a 7.3 Powerstroke F-250
The common 7.3 intake job is not a kit. It is the stock airbox coming out and a big round filter going on a short piece of 4 inch tube.
The Short Answer (TL;DR)
On this Ford-Trucks write-up, the 6637-style intake starts by pulling the battery so four bolts on the battery tray and airbox base can come out. The tray gets cut down to only the battery portion, a piece of 4 inch tube adapts the filter, and a hole is drilled for the factory filter minder. The thread does not give bolt sizes or the drill size. A bolt-on intake for the 1999-2003 7.3 F-250, F-350, and Excursion skips the cutting.
What the write-up used
- A 6637-style air filter
- 4 inch outside-diameter tubing, exhaust tubing in this case
- A T-bolt clamp at the filter
- A file or 60 grit sanding sponge for the cut tray edges
- The battery out of the way so the tray bolts are reachable
The Step-by-Step Process
Get the airbox base out
The short version in the thread is to unbolt the stock airbox, add 4 inch tube, and clamp the filter on. This writer went further and removed the battery first, then the four bolts that hold the battery tray and filter base. The whole base comes out.
Cut the tray and fit the tube
Cut away everything that is not battery tray. File or sand the sharp edges. A piece of 4 inch exhaust tube becomes the filter adapter. Drill a hole so the factory filter minder still threads in, instead of guessing when the filter is dirty. The thread does not say what size that hole was.
Clamp it
The writer used a T-bolt clamp at the filter. The photos in the thread show the filter sitting where the airbox was, with more room around it. Put the battery back on the cut-down tray.
The bolt-on version
That job throws the factory airbox away and leaves an open filter in the engine bay. If you want the same truck to breathe without cutting the tray, the store sells a cold air intake for the 1999-2003 7.3 Powerstroke in the F-250, F-350, and Excursion. Match the year and the 7.3 before you order. It is not the 6637 filter from the thread.
Shop the 7.3 Powerstroke cold air intake
Frequently Asked Questions
Is this the same as a cold air intake kit?
No. This thread is an open filter on a short tube, built from a 6637-style element. A kit keeps a tube and a shield and does not ask you to cut the battery tray.
Does the filter minder still work?
Only if you drill for it and install it in the new tube, which is what this writer did. The thread does not give the drill size.
Source: Ford-Trucks 6637 filter install. The install photos stay on that thread.
