Anyone have a SWB fleet, 2WD leaf springs & rear sport bumper? Could use some help

[71CHEVYSHORTBED402]

I had another thread out there, but it was a mess and no responses, so starting over

My truck is a 2WD, SWB C-10 with rear leaf springs. For what it's worth, the truck had a factory step bumper. The sport bumper brackets I got read for 4x4, but the vendor says they're correct for 2WD as well. From here I don't see what they're for. It's the inner bracket that's the problem, I think all outer brackets are the same.

The images show where I'm at. Makes it difficult not having the right bolt pattern, but I think I'm on the right track. Any input appreciated, especially those with a SWB 2WD fleetside with leaf springs. GMC anyone? - I believe they're primarily leaf springs.


Other than that:

It would go a long way if someone could tell me the distance from the frame rail to the bumper mounting surface. I suspect it doesn't matter leaf spring or coil on a SWB. Seems a SWB 4x4 would be the same. Maybe even a LWB, because my C-20 has a similar bolt pattern used for a step bumper.

Strikes me the brackets for a coil spring truck may be a better option. Thank you.


Some links:

Post 10 shows the brackets mounted. I think it's a SWB coil spring truck. It's mounted consistent with image 2 (bolt patterns A & B): http://67-72chevytrucks.com/vboard/s...d.php?t=488496

Some coil spring brackets. One is wrong, the holes in the brackets are supposed to face up for gravel guards, but it probably works without them. http://67-72chevytrucks.com/vboard/s...d.php?t=307775

This guy had the same issue as I d. Appears he ended up using the brackets for a coil spring truck. Post 3 is a mystery, he's using three bolts: http://67-72chevytrucks.com/vboard/s...d.php?t=634044

Same problem, and he ran with brackets for a coil spring truck as well: http://67-72chevytrucks.com/vboard/s...d.php?t=213260

[71CHEVYSHORTBED402]

I think at this point, just looking for confirmation I'm on the right track. Some confirmation or other. If you have a similar truck or experience, I'm all ears.


Bump for bumpers

[71CHEVYSHORTBED402]

SUCCESS: I put this on another venue and got a golden response. The guy has two 67 SWB GMC trucks with rear leaf springs. Not sure if they're 2WD or 4WD yet, I suspect they're 2WD. 4x4 may not be relevant anyway.

One of his trucks has the original sport bumper and brackets, and those brackets are shown below. On top of that he tried using the "4X4" brackets to install a sport bumper on his other 67, which didn't fit. He ended up with the brackets for a coil spring truck, made a slight modification to the bracket to clear a rivet and done. He's going to provide a picture of his replacements later tonight.

The original brackets look far more like the replacements for a coil spring truck. They appear the same less a small mod to clear a rivet on a leaf spring truck.

I haven't a clue what the brackets I have fit. Maybe a LWB. It's a good bet they're not for a 2WD SWB leaf spring truck. BTW, page 449 in the assembly manual

[71CHEVYSHORTBED402]

On a side, I have some mangled up original brackets that are similar the replacements in the OP. Anyway, the nuts are the same as what I found on my front bumper.

Couldn't tell you what they're called ("slotted hex nuts"). Other than appearances, I don't see a difference between these and a common hex nut.

[chewychevy67]

My 67 swb 2wd leaf spring had bumper mounts the same as coil spring trucks. The brackets fit just fine. Now I can't say if they were factory because it is a 67 gmc and had no spid from factory. I don't have it assembled but there all powdercoated in a box in my basement so I can't take measurements for you.

[randy500]

Your brackets are reproduction, I can tell by how they are formed where the bumper attaches, you wont like how they fit and they will bend your bumper around the bolt holes. Problem is they are not formed right in that area.
As to your question, I think the brackets you have are 4wd, maybe even blazer, they have the added reinforcement. It should be the same bracket except the upper curved lip which is clearance for the last bed bolt has been cut away and the reinforcement added. That being said maybe one of the holes was drilled wrong, compare them to your bent brackets to confirm the proper hole location, it should be essentially the same bracket but cut away like I explained.

[71CHEVYSHORTBED402]

Originally Posted by chewychevy67

My 67 swb 2wd leaf spring had bumper mounts the same as coil spring trucks. The brackets fit just fine. Now I can't say if they were factory because it is a 67 gmc and had no spid from factory. I don't have it assembled but there all powdercoated in a box in my basement so I can't take measurements for you.

Very cool. I think I'm beyond measurements at this point. The bumper should be 8.5" from the frame rail.

As you say, strikes me the brackets may have been EXACTLY the same as a coil spring truck. If the only condition is to avoid a single rivet on a SWB leaf spring truck, I see no reason why GM would make two different brackets.

[71CHEVYSHORTBED402]

Originally Posted by randy500

Your brackets are reproduction, I can tell by how they are formed where the bumper attaches, you wont like how they fit and they will bend your bumper around the bolt holes. Problem is they are not formed right in that area.
As to your question, I think the brackets you have are 4wd, maybe even blazer, they have the added reinforcement. It should be the same bracket except the upper curved lip which is clearance for the last bed bolt has been cut away and the reinforcement added. That being said maybe one of the holes was drilled wrong, compare them to your bent brackets to confirm the proper hole location, it should be essentially the same bracket but cut away like I explained.

YEP.....I was warned about the repop. brackets, the bumper surfaces aren't flat. They have to be flattened out or you'll toast the bumper.

The brackets I got are wrong for this application. Yes they're for 4WD, but rumor is they're correct for a 2WD leaf spring truck as well. I believe the truck has the correct bolt pattern on the frame (image 2). It's a common bolt pattern, perhaps 4x4 is different. While it's hard to judge, my 2WD C-20 has a step bumper and the bolt pattern is within 1/4".

As for my old brackets, I don't remember what I pulled them off of, it was so long ago. This reminded me that I hired some guys to remove the step bumper and install these for the sport bumper. A receiver hitch was added later. They're exactly like the replacements in the OP, and they were drilled right where it shows in image one. I always suspected something wasn't right, and I managed to dent up a new bumper when I slapped it on. 25 years later, this is a do-over

[71CHEVYSHORTBED402]

Originally Posted by 71CHEVYSHORTBED402

SUCCESS: I put this on another venue and got a golden response. The guy has two 67 SWB GMC trucks with rear leaf springs. Not sure if they're 2WD or 4WD yet, I suspect they're 2WD. 4x4 may not be relevant anyway.

One of his trucks has the original sport bumper and brackets, and those brackets are shown below. On top of that he tried using the "4X4" brackets to install a sport bumper on his other 67, which didn't fit. He ended up with the brackets for a coil spring truck, made a slight modification to the bracket to clear a rivet and done. He's going to provide a picture of his replacements later tonight.

The original brackets look far more like the replacements for a coil spring truck. They appear the same less a small mod to clear a rivet on a leaf spring truck.

I haven't a clue what the brackets I have fit. Maybe a LWB. It's a good bet they're not for a 2WD SWB leaf spring truck. BTW, page 449 in the assembly manual

He confirmed his trucks are 2WD. Safe to say a 2WD SWB with leaf springs and a sport bumper use bumper brackets for "a coil spring truck".

[MDPotter]

What was your final determination on this? I bought the same repop brackets from post #1 and I have a 2WD LWB with leaf springs and I have the same problem - I don't have a hole in the frame rail for the very front bolt hole in the brackets. My truck came with a step bumper and the front hole in the frame appears to be positioned correctly up and down on the rail, but needs to be about 2.5" forward. I am planning to use that same centerline to drill the hole, but wanted to find out where you ended up to make it work on yours. I would rather drill a couple holes than buy a new set of brackets.

[71CHEVYSHORTBED402]

Originally Posted by MDPotter

What was your final determination on this? I bought the same repop brackets from post #1 and I have a 2WD LWB with leaf springs and I have the same problem - I don't have a hole in the frame rail for the very front bolt hole in the brackets. My truck came with a step bumper and the front hole in the frame appears to be positioned correctly up and down on the rail, but needs to be about 2.5" forward. I am planning to use that same centerline to drill the hole, but wanted to find out where you ended up to make it work on yours. I would rather drill a couple holes than buy a new set of brackets.

Attachment 1869868

I'm surprised your frame doesn't have a hole where you've marked. Both my SWB and LWB have that hole, and both were factory step bumpers.

The downside of drilling through that bracket where you've marked (hole) is it's not all that secure. It will leave an open hole or close, see the picture in post 8. Not that it can't work, the brackets I had for my sport bumper were the same. I think I pulled them off a Blazer, it was a long time ago.

I haven't ordered them yet, but plan to run with what's in post 3 and use the "coil spring" brackets. The coil spring bracket needs a slot cut out to clear the rivet. I have no idea what your brackets and those in the OP are for. They supposedly for a SWB leaf spring truck, but I'm going to say no. Obviously there were some variances.

[MDPotter]

Originally Posted by 71CHEVYSHORTBED402

I'm surprised your frame doesn't have a hole where you've marked. Both my SWB and LWB have that hole, and both were factory step bumpers.

The downside of drilling through that bracket where you've marked (hole) is it's not all that secure. It will leave an open hole or close, see the picture in post 8. Not that it can't work, the brackets I had for my sport bumper were the same. I think I pulled them off a Blazer, it was a long time ago.

I haven't ordered them yet, but plan to run with what's in post 3 and use the "coil spring" brackets. The coil spring bracket needs a slot cut out to clear the rivet. I have no idea what your brackets and those in the OP are for. They supposedly for a SWB leaf spring truck, but I'm going to say no. Obviously there were some variances.

The hole where I marked does exist in the frame rail, but I don't have that hole in the bracket. I am thinking about drilling a hole in the frame (furthest hole forward in the bracket) though. It looks like I should have gotten the coil spring brackets, but I can make this work.

[71CHEVYSHORTBED402]

Originally Posted by MDPotter

The hole where I marked does exist in the frame rail, but I don't have that hole in the bracket. I am thinking about drilling a hole in the frame (furthest hole forward in the bracket) though. It looks like I should have gotten the coil spring brackets, but I can make this work.

I think that will work for you as well. Doesn't on a SWB because the leaf spring brackets are in the way.

[randy500]

I think this is the deal on the rear bumper brackets...

The catalogs are wrong.

There are 2 styles of inner brackets shown in the pictures above.
The one with the top cut away and the thick metal reinforcement welded on is for 69-71 blazers. The cut away is needed to clear the last body rubber mount that is under the frame in that location. 72 blazers do not need this bracket because the frame was modified so that no inner bracket was needed. It’s very difficult to install a bumper bracket on a blazer because the forward hole is blocked by the gas tank so in 72 they fixed the clearance problem with the frame re design.

As seen in the above picture the regular bracket fits a 67 short wheel base leaf spring truck and all other trucks except blazers 69-71 4wd and 2wd. And all 4 wd tucks have the longer bracket with longer bolt hole spacing.
I think thE rear bolt hole is common to all the brackets which spaces the bracket from the frame.

I think the leaf spring frames on short wheel base trucks one of the rivets interferes with the bracket, drill a hole for clearance if required.

[randy500]

Someone post the distance from the bumper mounting surface to,the first hole for both style brackets, I think it’s the same distance. Also post the distance between the mounting holes.

Ignore the first hole on the reinforced bracket, don’t know what it’s for but it’s not a mounting hole. That hole is shown in picture 1 of post 1

[randy500]

Picture on of this post shows the 2 styles of brackets side by side. The lower bracket doesn’t have the reinforcement welded onto it, I think the early ones were like that and tended to bend as shown in the picture.too.

I went out and checked my long bed 4wd and it needs the longer reinforced bracket.


http://67-72chevytrucks.com/vboard/s...d.php?t=163508

[MDPotter]

In lieu of buying the other style brackets, it looks like I can mount it as planned, but I need to drill the frame rail for the forward most hole. Post #1, image #3, I had the bracket positioned just like that and had the same issue shown in image #4 - there is not a hole in the frame for the forward most hole in the bracket. If I do this, it appears the bumper will be in the correct position. When I was test fitting the brackets, I also attached the bumper (loosely) to the brackets and it appeared to land in the right spot.

I do have two holes in the frame from the original step bumper, but the forward most hole is covered up by the bracket (just like the picture in post #8). What I will do is draw a line through the centerline of both holes in the frame and use that to locate the centerline of the forward most hole in the bracket for drilling of the frame.

I also need to flatten out the end of the bracket that attaches to the bumper as it is not flat and could damage my bumper as I tighten.

Once I get all of this done, I will report back the results.

[Low Elco]

Glad you threw this up, I'm late to the party. I'm converting a 67 GMC over to coils and have the bumper brackets from the coil truck as well. I was wondering how this'll all go together. Thanks!

PS- I have a location in Reno I occasionally get to go to, I gotta come visit next time. Are you doing anything with the Reno C10 club?

[71CHEVYSHORTBED402]

Originally Posted by randy500

I think this is the deal on the rear bumper brackets...

The catalogs are wrong.

There are 2 styles of inner brackets shown in the pictures above.
The one with the top cut away and the thick metal reinforcement welded on is for 69-71 blazers. The cut away is needed to clear the last body rubber mount that is under the frame in that location. 72 blazers do not need this bracket because the frame was modified so that no inner bracket was needed. It’s very difficult to install a bumper bracket on a blazer because the forward hole is blocked by the gas tank so in 72 they fixed the clearance problem with the frame re design.

As seen in the above picture the regular bracket fits a 67 short wheel base leaf spring truck and all other trucks except blazers 69-71 4wd and 2wd. And all 4 wd tucks have the longer bracket with longer bolt hole spacing.
I think thE rear bolt hole is common to all the brackets which spaces the bracket from the frame.

I think the leaf spring frames on short wheel base trucks one of the rivets interferes with the bracket, drill a hole for clearance if required.

Yes, a rear shackle mount rivet is in the way on a SWB leaf spring truck, but not by a lot. I've seen some install them as is, but agree, cut or drill the bracket for a clean job.

If I understand you right, you're saying the longer bracket (with cut-away & repops include a reinforcement plate) fits 67-71 2wd & 4wd Blazers, and all 4WD trucks.....................Every other truck takes the "regular bracket". I think you're onto something and may have nailed it. Seems to me repop. brackets have nothing to do with coils and leaf springs. Regardless you're right, the "catalogs" are wrong.

Wouldn't be the first time vendors were confused by what was. I'm reminded of the hard line pump to carb on a BBC. They show A/C and non-AC. Unconfirmed, but it probably has nothing to do with A/C and everything to do with a return line to the fuel tank. Then there's the "A/C 402 has a return line to the fuel tank". Neat story


Nice job MDPotter. If the bumper looked right you're probably good. You figure the bumper mounting surfaces are plumb, parallel the frame or?

[71CHEVYSHORTBED402]

Originally Posted by Low Elco

Glad you threw this up, I'm late to the party. I'm converting a 67 GMC over to coils and have the bumper brackets from the coil truck as well. I was wondering how this'll all go together. Thanks!

PS- I have a location in Reno I occasionally get to go to, I gotta come visit next time. Are you doing anything with the Reno C10 club?

Sounds to me you have the brackets in post 3, and they should work fine. If yours is a SWB, then I believe you'll just have space where it cleared the shackle rivet (post 3, image 2).

Look me up dude. I'm in the middle of restoring this. Need to drop the engine/trans, front coils and steering for a finished chassis, then it's all about paint prison. Never heard of a Reno C10 club, be nice to meet common interest.

[randy500]

Originally Posted by MDPotter

In lieu of buying the other style brackets, it looks like I can mount it as planned, but I need to drill the frame rail for the forward most hole. Post #1, image #3, I had the bracket positioned just like that and had the same issue shown in image #4 - there is not a hole in the frame for the forward most hole in the bracket. If I do this, it appears the bumper will be in the correct position. When I was test fitting the brackets, I also attached the bumper (loosely) to the brackets and it appeared to land in the right spot.

I do have two holes in the frame from the original step bumper, but the forward most hole is covered up by the bracket (just like the picture in post #8). What I will do is draw a line through the centerline of both holes in the frame and use that to locate the centerline of the forward most hole in the bracket for drilling of the frame.

I also need to flatten out the end of the bracket that attaches to the bumper as it is not flat and could damage my bumper as I tighten.

Once I get all of this done, I will report back the results.


Attachment 1870429

Fixing that bumper bracket is almost impossible, it can be flattened and rounded a bit but even then you can’t tighten up the nut or it will, unless perfect, dent the bumper. I recommend after doing what you can with it to just barely tighten up the bolt using a star washer to keep the nut “tight”

[71CHEVYSHORTBED402]

Originally Posted by randy500

Fixing that bumper bracket is almost impossible, it can be flattened and rounded a bit but even then you can’t tighten up the nut or it will, unless perfect, dent the bumper. I recommend after doing what you can with it to just barely tighten up the bolt using a star washer to keep the nut “tight”

Been there done that. When I first got the bumper, which is probably a re-chromed original, I thought nothing of it and dented up my new bumper. Tried some rubber washers, didn't help much. That was a quarter century ago using original brackets and nice surfaces, though the wrong brackets. Pretty sure I pulled them off a Blazer.

That will be my last expense, re-chromed and straightened bumpers. Nice idea on that star washer.

[MDPotter]

For anyone with a LWB 2WD leaf spring truck, the non-coil spring brackets will work. Thanks to the heads-up earlier in this thread, I heated up the end of the inner bracket that attaches to the bumper to flatten it out. I then attached the brackets to the bumper and installed (1) bolt in each frame rail to mock up the bumper and I drilled (1) hole in each rail for the forward most hole in the bracket and it looks great. I neglected to take a picture of the bumper itself, but here is a picture of the bracket setup:

[71CHEVYSHORTBED402]

Originally Posted by MDPotter

For anyone with a LWB 2WD leaf spring truck, the non-coil spring brackets will work. Thanks to the heads-up earlier in this thread, I heated up the end of the inner bracket that attaches to the bumper to flatten it out. I then attached the brackets to the bumper and installed (1) bolt in each frame rail to mock up the bumper and I drilled (1) hole in each rail for the forward most hole in the bracket and it looks great. I neglected to take a picture of the bumper itself, but here is a picture of the bracket setup:

Attachment 1872239

NICE............And nice clear picture of bracket orientation - frame and bumper.