Use a 73-87 Stepside bed on a 67-72

[Palf70Step]

Finally decided to compile what I did to make a 73-87 stepbed look and fit on a 67-72. Now these were all done to a shot wheelbase model, but I assume you will need similar steps to do this for a long step, although I think those are quite rare for 73-87. I went this way because 67-72 trucks are very rare in our salvage yards. Most still appear to be work trucks. To use after market sheet metal was very expensive and i didn't have a vendor very close to me.

First couple shots show what I had to deal with. The original owner had welded in a steel plate for a bed in order to haul cattle. In the process the drain for the bed was sealed. Age, weather and cattle pee ate my bed up.

After stripping the steel plate and the little bit of original wood out here is was I was working with.

[Palf70Step]

I found a really good shape bed from an 84 GMC, and I heard and did some measurements and found it would fit. Brought the bed home and took off the steps and fenders.

[Palf70Step]

Now to work.

I discovered it was not exactly a bolt in swap. Several areas differ on the newer bed, but are easily fixable, especially if your a better welder than I am (almost anyone is)

First areas I discovered that were different were the fender mounting holes are all way different and the front side of the bed is shorter by a couple inches because of the different style steps.

Fenders first.
I measured (several times) on the old bed sides and marked a spot on the newer bed for the top center hole of a step fender.

I then mounted the fender with one bolt and used two scisor clamps at the front and rear lower corners of the fender. Basically I measure and eyeballed till I saw the fender was where it should be. Then I clamped it into place, and used a sharpie to mark the new hole positions.

I removed and drilled the new holes, then bolted on the fender (temporarily). I thought it came out good, so I then did the driver's side.

The last picture shows the difference in bed side lengths that has to be corrected

[Palf70Step]

About this time I discovered yet another difference I hadn't noticed before. The two mounts on the rear cross brace were different lengths. The newer bed is shorter. (first 2 pictures).

You could just replace the rear cross brace, but mine was shot to heck, so I decided to try and removed and swap the mounts from the old sill to the newer one.

Just drill out the old welds and mine came off with a slight tap of a cold chisel.

At least on mine, the top weld holes of both clamps were the same. I drilled out the center hole on the new bed sill and the old brackets and used a drill bit to ahold and allign it until I could clamp it into place. I kept the bit in until it was tacked in.

[Palf70Step]

I felt pretty good about this as it was my first use of a mig welder and first time in about 30 years that I even touched a welder. I did a little over kill on the welding I think, but I wanted to make sure it stayed. After I cleaned up the welds, I clean the area good, coated the parts with a rust converter and rustolium paint

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Now for the sheetmetal part.
First thing you will need to do is cut/grind off the lip where the steps hung on from the newer bed (pic 1)

Rather that fabricate a piece from new flat new metal, I checked the original besides closer and found I could cut off the lower portion and be able to use it as my extension. (pic 2)

Remember, measure alot before you cut!!! I goofed when I cut the old bed, so I had to add about a 1/2" spacer. The top of bed to the step mount should be 22 1/8". I cut and welded in a filler piece of 18 gauge plate steel. It not gave me the extra 1/2" I needed, but by being a backing it added some strength to the area. Go SLOW and space out your welds. You don't want to warp it.

Remember I am not a good welder. I spent about a day for each bed side.

[Palf70Step]

While I was adding the extra metal I also filled in the old holes. This helped occupy me and keep my patience while I was welding the step extension. I put a few tacks on the step, then weld a hole or two. Then go back to the step. I did this till they were all filled and looked OK after the grinding.

AGAIN BE CAREFUL HERE. YOU CAN HEAT UP THE BED REAL FAST WITH A GRINDER AND CAUSE IT TO WARP.

I had heard mixed reviews about using the wet towel thing to cool the metal, so I didn't do it. I just let it cool naturally and tried not to heat it too much. I think that and my inexperience is was made it take a whole day to do the one bed side.

I welded the back side of the add in brace, sealed it good with JB welds around the edges, coated it with rust preventor stuff . I just used some white rustolium on the old step mounting holes, because I'll be doing some final sanding and finishing later.
Side one finished.

[Palf70Step]

Side two went quicker. I didn't mess up the cut of the piece from the original bedside.

Again had I been a better welder, this might have gone a lot faster and probably look nicer too.

Anyways three days of work (so far) and I have a a decent bed to put on the truck.

[Palf70Step]

As an added note, you'll need to have a front cross with mounting holes for the step. The 84's bed looked like the holes were different, so I cleaned, rust coated and painted my original front cross rail. I used the others from the 84 since they were in better shape.

Added note: I knew I was not doing my bed in the original wood. I'm using a fiberglass coated piece of plywood with a piece of polished diamond plate on top. I couldn't get the original bolts out of the side pieces, so I just drill the heads out. They didn't look neat, but since the diamond plate would cover it or a new bolt head, I wasn't too worried.

Here she is already to be final sanded, painted and put back on.

[Palf70Step]

I had a total of 3 to 4 days of work in this at my slow do it out in the weather pace. However when it was all said and done, I had a decent bed for the cost of a tube of JB weld, can of spray rust convertor, rustolium paint, some welding wire, and the bed. For me that was under $200. Oh yeah, about 3 or 4 bandaids . What can I say, I am not all that coordinated.

Hope this helps some of you with an alternative to buying new bed sides.

[krue]

Not to step on Bill's thread, but here's some detail that I was asked to provide.

First the measurements I got off of my 70 stepside bedside. The numbers and lines are color coordinated.

[krue]

Here's some numbers to get you started on your fender holes. All measurements are to the center of the hole.

Hole #1 3 1/2" from the TOP, 39 1/8" from the FRONT

Hole #2 14 3/4" from the TOP, 15" from the FRONT

Hole #3 14 3/4" from the TOP, 4 11/16" from the BACK

[krue]

Finally, some measurements for the stock taillight and back up light brackets.

Hole #1 2" from the bedside, 3 1/2" from the bottom of the stake pocket.

Hole #2 2 3/8" from the bedside, 10" from the bottom of the stake pocket.

here something I saved

[Palf70Step]

Good job Krue. I forgot to measure those before I trashed my old bed sides!!

[Palf70Step]

added picture