For most truck guys, putting an air ride system on their truck means notching the frame to create clearance for the axle.  This is a tutorial on installing a step notch on a Chevy S10 pickup, but the same principles apply to virtually every vehicle that gets lucky enough to have one of these installed.  

This install was done by the fellas at Suicidedoors.com , namely Jason, and his two brothers, Luke and Adam.  Luke turned the wrenches, Adam did the welding, and Jason kicked back to play boss and take pictures.  Overall, the process took around 10 hours to do from pulling the bed to laying the last bead.  10 hours may seem like a lot, but the goal is to do things right the first time.  So kick back, relax, and enjoy the tutorial. 

This pic is right after we pulled the bed off. Very familiar site to most of you I'm sure.	Here is after pretty much all of the stuff was stripped out.	We scraped all of the undercoating off in the notches future home area with a puddy knife.
Then we wiped the rest of the gunk off with a rag and brake cleaner. That stuff works really well.	Goodbye brake line hanger.	We felt that the old shock crossmember was in the way, and ugly. The plasma made it easy to remove this.
Here is the frame again, a little cleaner this time.	We threw the axle back in there to find dead center of the notch. We took the time to lift the entire truck off the ground and get it perfectly level. When the frame was level, we were able to put another level on the center of the axle to find our center point in the frame.	Once we marked the frame where the center of the notch would be, we double checked our measurements from a few different places to make sure we were exact. This pic shows a measurement being taken from the bolt sitting in front of the spring hanger. 28-13/16" is what we got. To make sure we didn't goof up, extra time was spent triple checking everything. Measure many times... cut once.
The remainder of the factory bumpstop was cut out of the way. It was interfering with the new step notch plate. I had removed most of the bumpstop 3 years ago when I first bagged it.	In this pic, Adam is cutting the bottom of the step notch plates off to match the shape of the frame. We clamped them in place and made sure they were perfectly level, then scribed a line in them even with the bottom of the frame. The plasma makes this job pretty easy.	The plate is then clamped in place to make sure it fits to our liking.
The inside of the frame rail on a S10 is jacked all to hell. It needs to be trimmed so that its parallel with the outside plate. The distance between the inside of the plates is 2-7/16". This pic shows the upper frame rail after its been trimmed.	After we marked the lines, a straight edge was clamped into place to make getting a nice cut a piece of cake.	Cut off disks are nice. They slice through S10 frames like a hot knife through butter. Here you can see the straight edge clamped in place with the cut off wheel being guided by it.
Once the top of the frame was cut, it was time to move to the bottom. The step notch plate was put in place and held level. Lines were then scribed on the frame to show where it needed to be cut. Because the notch plate was level, we needed to measure inward past the line a 1/8". That is where the cut will be made to allow for a outside corner to be welded up.	A straight edge was clamped in place here too. It makes cutting a straight line so much easier.	After the frame was trimmed to parallel, both of the inside plates were tacked in first. In our opinion, they are the most crucial to get aligned perfectly.
With both of the inside plates tacked in, we sat 2 pieces of square tubing on top of them. The tubing acts as a stop when clamping the outside plates on. This way you can make sure they are perfectly straight across from each other. Using 2 levels, we double checked to make sure the frame was still level, and that the notch was too.	If you look closely, you can see a metal spacer between the 2 notch plates. This helps in keeping everything aligned. This spacer gets welded in place and will stay there forever.	Here is the spacer welded in place. If you don't have this in there the notch plates will bow in when you weld the frame to the inside of the notch plates. If it bows in, the top cap will not fit properly.
The top of the frame is then welded to the step notch plates.	Next, the bottom of the plates are welded to the frame	Now that the frame is solid in the notch area, we can cut the frame out that's in the center of the notch. Again, cut off disks rule. You have more control over a hand grinder, then a sawzall. A sawzall will work great too though.
The center has exited the premises and was chucked across the shop.	When using a cut off disk, wear a face shield and gloves. Sometimes they catch and explode. You can lose and eye or get disk debris stuck in your face. Not good.	It is now time to fit the top cap. Since the frame is not square, it has to be trimmed to fit. We made a template out of poster board and transferred the shape to the cap. Then zipped it up with the plasma.
When the top cap fits like you want, take it in place.	On the driver's side, you have the tail light wiring to deal with. here we cut an access hole to run the wires inside the notch. It will shorten the overall length of the wires some, so you may have to add a few inches to get reconnected.	Here is the access hole. You will need one on both sides of the driver's side notch. Make sure to smoothen the jagged edges. Editors Note: I recommend doing this on both sides of the frame, incase you choose to run wires to the back on the passenger side for valves or compressors.
The top cap is now being fully welded in place. The pic doesn't do justice to how smooth by bro's beads are. I'm jealous.	Here is another pic of the top cap and the outside plates getting fully welded.	The top cap is now finished. The inside cap has been trimmed to fit and tack welded in place.
After the inside cap is tacked and checked over, it is fully welded.	Here they are. All done... almost. They still need to be coasted with either some good paint, or undercoating to keep them from rusting. This frame will now lay out on 20's easily. I think it might even lay on 22's.	Now you don't have to go through all the crap we did to install a step notch. It just depends on how much time you have and if you want to move around inside the frame. It makes the install go a lot smoother and cleaner.