Update: More step installation info!
This is just an update about the steps used on our Blazer. These images hopefully will clarify some of the process of installing the steps using the custom bracket adapters discussed here and in an earlier post:
https://www.thedieselpageforums.com/...113#post338113
https://www.thedieselpageforums.com/...8&d=1757976711
This is looking straight down over the driver's side step. The bracket adapters produce a step installation that results in a level (the centered bubble shown above) stepping surface. The horizontal oriented bubble level simply indicates that the Blazer has a slight nose-down attitude. The remainder of the step frame is parallel to the lower body of the GMT-400 OBS truck/SUV. Remember, these steps were originally designed for the 2007-2019 Jeep Wrangler 2-door models. They stopped making them for the OBS trucks, so the bracket adapters shown here solve the problem.
https://www.thedieselpageforums.com/...9&d=1757976711
The bracket adapters shown on the left side in this photo attach to the factory brackets shown here on the right. The adapters themselves don't carry the weight on the steps, instead they provide stability to maintain a level step - i.e. keep them from twisting when stepped on. The full weight is carried by the 1" angle steel (shown above and below) that bolts to the lower pinch weld seam on the vehicle body below the doors of the truck/SUV. This arrangement is more than adequate even when a big guy is on the step.
https://www.thedieselpageforums.com/...0&d=1757976711
These are the 1" angle steel that sits on top of the pinch weld, and will be bolted to the pinch weld using two button-head 6mm bolts. I used 1/4-20 bolts/nuts and washers to bolt the 1" angle steel to the factory brackets. No washers are used on this side of the 1" angle...
https://www.thedieselpageforums.com/...1&d=1757976711
The above is just another shot of the brackets parts - from underneath, showing how they attach to each other.
https://www.thedieselpageforums.com/...2&d=1757976599
You're looking at the back side of the left front mud flap in the lower left quadrant of this photo. If you have a 2500/3500 truck or diesel SUV, your vehicle likely has plastic factory front wheel flairs. To get these steps installed you'll need to cut a relief in the bottom of each flair for the forward pointed end of the steps to fit... like that shown here. I used a Dremel tool with a carbide bit, but there are likely many other ways to make a neat cut without removing the wheel flairs. The cut can't be seen from above.
https://www.thedieselpageforums.com/...3&d=1757976599
Once you've loosely assembled the steps, you can hang the steps onto the lower pinch weld. This will allow you to mark where the 1" angle steel pieces will fit. Once you've marked where the 1" angled steel will sit, remove them from the brackets and clamp them to pinch weld. Use a center punch, then drill two 1/4" holes through the pinch weld seam and the 1" angle steel. Try to center the hole in the 1" dimension of the angle steel, without getting too close to the edge of the pinch weld. Btw - I used very lightly clamped Vice-Grips here just for photo purposes. In actual practice, I recommend using duct tape for cushioning, along with C-clamps.
https://www.thedieselpageforums.com/...4&d=1757976599
However, the underneath area of the pinch weld includes some water drain channels that could interfere or prevent the 1" angle steel from sitting flat.
https://www.thedieselpageforums.com/...5&d=1757976599
Mark where that interference is, and use an angle grinder to cut a relief area like that shown here. The angle steel will still provide plenty of strength. Try to get the holes drilled for the 6mm button-head bolts (in the top surface of the angle steel shown here) somewhere between the two bracket bolts shown here. Exact hole spacing isn't that important. Convenience is a factor. That's why I didn't pre-drill the 1/4" holes for the button-head bolts. It's hard to know exactly where the button-head bolts will need to go till you begin assembly. Besides, drilling the 1/4" holes for the button-head bolts while clamped onto the pinch weld seam means it'll fit together exactly.
https://www.thedieselpageforums.com/...6&d=1757976599
Once the holes have been drilled and any clearance cutouts are made, apply paint or caulk to prevent rusting, and loosely bolt the 1" angle steel onto the pinch weld seam using the 6mm button-head bolts/washers/lock washers. Don't use a flat washer against the lower surface of the pinch-weld. The flat washer isn't necessary, and the step frame itself will fit that much closer to the body of the vehicle.
https://www.thedieselpageforums.com/...7&d=1757976599
DF = Driver Front, DR = Driver Rear
The factory front and rear brackets are slightly different from one another. There is enough adjustment to allow the custom bracket adapter to work just fine for either the front or rear factory bracket (all 4 of the adapters are the same). Remember, leave all of the hardware loose till everything has been loosely bolted together. Hold or clamp the steps into position as you then tighten all of the hardware. I installed the Blazer steps by myself, but another set of hands could be a help here.
The pics for this update were shot using a new set of bracket adapters I fabricated recently for a reader. If there was a need for many more, I'd hand over the design to my friend the fabricator so he could make them. Let me know...
As of 9/15/2025 - current source for these Magnum steps: https://www.summitracing.com/parts/rpt-rts46jp