Just did the Brothers LWB to SWB conversion...

[RedRider]

Overall pretty straightforward with no major issues and only a handful of curse words. I thought I would add some some suggestions and tips from someone with standard mechanical skills within the confines of a two-car garage.

First off, the instructions from Brothers were VERY detailed and provided an excellent step-by-step procedure. These are just some additional details I hope will be helpful to others doing this conversion.

My truck had the "spoon like relief" in the frame, and the template was slightly impeded by it. I had to grind it down just a tad so that the template would sit flush. If you have this, you should only need to take a little off for it to fit properly:


Next were the cuts. The cut under the cab was the most challenging, as there was limited cab clearance to start the initial top cut. I found a 6" sawzall blade perfect for such a tight space, yet long enough to make it across the whole frame:



Once the rear is rolled out, I tackled the bed and cab mount rivets. There are several ways to approach this but I stuck with the sawzall and removed the heads, then punched the rest through. If you go this route, be very careful not to damage the cab mounts (like I did) since they have to be relocated and reused.



When relocating the cab mounts, I recommend drilling a 1/8" pilot hole like the previous holes for the other two 3/8" cab mount holes. They should relocate right next to (but below) the remaining cab mounts:



Once you're ready to bolt in the channel support, don't forget the top and bottom bolts on for the rear connection (only bottom for the front):



Fitting the c-channel into the cut sections is where you'll need some help. I was under the cab fitting the sections while my wife pushed from the rear.



Also, while you're under the frame bolting it all together, you'll need to configure the two lower side bolts with the two bolts on the bottom. You can't have them both facing "bolt-out" because you won't be able to get nuts on them. I made the side bolts outward and the bottom bolts inward:




I was nervous and wanted to make sure every bolt was tight. In doing so, one broke. Fortunately Brothers provides a few extra nuts, bolts and washers in their hardware kit so don't worry if you break or lose one:



The rear frame cuts are easier since they're so accessible (and you can sit your beer on the frame while you cut). To mark both the cut and the top bumper hole, I hit it with some spray paint, then used a square the scribe a line down the side.





Again, use a 1/8" pilot to make the two 1/2" holes that will make the top oval. I used an old milling bit to hone out the rest of the oval.

I went to drill the "bump" side holes, but they were already there. Does anyone have info on this?


Then you're done! It's that easy
Before:

After:

[RedRider]

Almost forgot: I haven't changed the cab bushings but noticed that I'm a good 1/2" off in the rear, which is scary.



Everything else lines up perfectly, and my measurements on each side are exactly the same. Maybe if I replace the front bushings first I'll get that extra 1/2 inch back?

[1968aj]

good information. I will be doing the same in a few months.what are you doing about bed?

[RedRider]

Originally Posted by 1968aj

good information. I will be doing the same in a few months.what are you doing about bed?

Fortunately I found an old SWB bed floor, then purchased new bedsides.

[jocko]

Thanks for sharing - lots of folks interested in this conversion - and especially the Brothers kit. I have to admit I'm kinda surprised the kit comes with Grade 5 rather than Grade 8 bolts (wouldn't have noticed if you hadn't twisted one off). I guess I'm kinda into overkill a little bit when it comes to bolts that hold my frame (or anything, for that matter) together, but I'm not at all implying that Grade 5 is not sufficient - I'm sure the engineering was done on this, just was surprising to me, that's all.

[leddzepp]

Looks good! I think once you install new cab mounts and get everything bolted back up it will sit square. I’m also surprised they didn’t include grade 8 bolts. My c notch and every other “bolt on” part I’ve used has always included grade 8 hardware. Lots of people interested in doing this since the cost of a swb frame is getting ridiculous

[Daaaanz67]

Poor LWB, looks good though nice kit grade 8 for me also. I like the overkill.

[RManson]

From Brothers' instructions:

BROTHERS recommends welding the frame together at the butted seam.

That's why the hardware is only Grade 5. It should be welded together.

We installed one of the first kits from Brothers and were very impressed...

http://http://www.hotrod.com/article...et-c10-trucks/

[hewittca]

Nice writeup. I've been interested about this kit. I've already done the SWB conversion, but it would have been nice to do it this way. One thing I learned along the way was that you need to move your carrier bearing bracket from the lower set of holes to the upper set. It raises the carrier about 3/4" and eliminated the vibration I had after doing my conversion. You may be able to get by without doing it but if you pick up a vibration, this will probably fix it.

[randy500]

The bumper "2nd" set holes are always there. I have measured them and they appear to be 1/8" off (closer to the bed) when compared to the original hole placement, they do work though.

I haven't used the kit, but have shortened many frames, if your very precise with your measurements the rear cab mount should line right up....on my crew cab I couldn't precisely move the rear cab mount back since I used 2 frames...to locate the rear cab mount I loosely bolted the mount to the cab with the rubber mount in place then set the mount height in relation to the frame, clamped the mount to the frame and drilled through the mount into the frame to locate the holes.

[RedRider]

As soon as it's street-worthy I'll get it welded up. The bolts alone would probably be fine, but a little extra assurance wouldn't hurt.

Originally Posted by hewittca

Nice writeup. One thing I learned along the way was that you need to move your carrier bearing bracket from the lower set of holes to the upper set. It raises the carrier about 3/4" and eliminated the vibration I had after doing my conversion.

I'm on the fence as to if I should cut-down the two-piece or switch over to a one-piece driveshaft. It would be nice not to have to worry about carrier bearing vibrations.

Originally Posted by randy500

The bumper "2nd" set holes are always there. I have measured them and they appear to be 1/8" off (closer to the bed) when compared to the original hole placement, they do work though.

Yes! just slightly off...closer to the bed. Good to know they'll work.

Before I go into panic mode regarding the bed mount alignment, I'll get the whole cab lifted up and pull/replace all four corners together. Hopefully that 1/2" got lost in the shifting of the frame and cab.

[tutone]

I think you are going to end up ok with your rear body mount. I cut mine and relocated the rear mount by measuring a factory short bed frame I already own. It looks like we ended up much the same. There is a factory hole in the top of the frame that is really close to being in line with the front two holes that you drill for your relocated body mount.

[rockyrivermark]

Originally Posted by RedRider

Almost forgot: I haven't changed the cab bushings but noticed that I'm a good 1/2" off in the rear, which is scary.



Everything else lines up perfectly, and my measurements on each side are exactly the same. Maybe if I replace the front bushings first I'll get that extra 1/2 inch back?

I was so angry. The template for that cab bushing mount relocation is 1/2" off.
Happened to me also
How in the heck do they not know this!
My bumper holes were already in frame also
Mark

[tutone]

Originally Posted by rockyrivermark

I was so angry. The template for that cab bushing mount relocation is 1/2" off.
Happened to me also
How in the heck do they not know this!
My bumper holes were already in frame also
Mark

I would be too. The measurement is an easy one. Measure from the front of the old cab mount (front hole), to the front of the new cab mount (front hole). Should be 12". If it isn't redrill.

[rockyrivermark]

Originally Posted by tutone

I would be too. The measurement is an easy one. Measure from the front of the old cab mount (front hole), to the front of the new cab mount (front hole). Should be 12". If it isn't redrill.

I know. We cut out 12" from frame so can mount should move 12". Simple right? But template is 1/2" off. Can't remember if too small or too large but definitely 1/2" off.
I emailed Them and got no response.
I angled the bolt in and it worked out but WTH
Posted via Mobile Device

[Daman]

I'm looking at doing this also this spring but to a K10. What was the time frame? A weekend, two weekends?

[rockyrivermark]

Originally Posted by Daman

I'm looking at doing this also this spring but to a K10. What was the time frame? A weekend, two weekends?

when we did it last year we started at 8am and was done by 2:00pm which included welding the seam, new brake line,cab mounts and reconnect the fuel lines
This of course did not include installing the new bed sides and floor.
its very easy. I paid $400 for the kit which is expensive but for me to made the process simple and basically fool proof.
good to have two sets of hands to help with the process.
I took by 2 piece driveshaft to a local shop to have it cut down and balanced (12" shorter). Since they already had it I had them install U joints.
one tip we found was:
when you bolt the inner U channel in the rear of frame and get ready to slide it back in, keep those bolts loose so you have wiggle room to maneuver it in the from frame channel. its a snug fit.
Mark

[GAc10boy]

Super helpful thread. Planning to do this with a lwb chassis I have soon.

[RedRider]

Originally Posted by rockyrivermark

I was so angry. The template for that cab bushing mount relocation is 1/2" off.
Happened to me also
How in the heck do they not know this!
My bumper holes were already in frame also
Mark

Just curious, did your frame have the relief lip?

Originally Posted by rockyrivermark

I know. We cut out 12" from frame so can mount should move 12". Simple right? But template is 1/2" off. Can't remember if too small or too large but definitely 1/2" off.
I emailed Them and got no response.
I angled the bolt in and it worked out but WTH

I did the same thing, and with some pushing and shoving it worked. I used a big screwdriver to align the rear holes the best I could, but it was definitely 1/2 inch off.

Originally Posted by tutone

I would be too. The measurement is an easy one. Measure from the front of the old cab mount (front hole), to the front of the new cab mount (front hole). Should be 12". If it isn't redrill.

Maybe they should add an additional step where a measurement between cab mount holes is made to verify you have that 12" there, and not 11.5"...before drilling.

[rockyrivermark]

Originally Posted by RedRider

Just curious, did your frame have the relief lip?



I did the same thing, and with some pushing and shoving it worked. I used a big screwdriver to align the rear holes the best I could, but it was definitely 1/2 inch off.



Maybe they should add an additional step where a measurement between cab mount holes is made to verify you have that 12" there, and not 11.5"...before drilling.

all they need to do it move the hole on the template 1/2". As thought out as that template is I'm amazed that a simple measurement is off like that.

[NC_John]

Good info guys. I was going to do this conversion this year but the cost of getting my bedsides shortened has forced me to wait another year or two. I am keeping my original paint so its $$$.

[Lanman1972]

I did this conversion tonight. Thank you for the info about the cab mount distance being incorrect. Using the template the mount would have been 1/2" off. I had all the preliminary stuff done and a buddy and I cut it and have it back together in 3 1/2 hours. MAKE sure to measure the 12" dimension for the cab mount. Thanks again for your post!

[RedRider]

Originally Posted by Lanman1972

I did this conversion tonight. Thank you for the info about the cab mount distance being incorrect. Using the template the mount would have been 1/2" off. I had all the preliminary stuff done and a buddy and I cut it and have it back together in 3 1/2 hours. MAKE sure to measure the 12" dimension for the cab mount. Thanks again for your post!

Right on, glad it helped! You plan to cut your existing driveshaft or go to a one-piece?

[Lanman1972]

I had the driveshaft shortened a couple months ago. All new u-joints, carrier bearing, cleaned and painted for $300. I have all new sheet metal for the bed, so almost done. Not really, still have to pull the engine for cleaning and painting.
Here is the project if interested.

http://67-72chevytrucks.com/vboard/s...d.php?t=704128

[otsa947]

Looking to do the same to my 72. Could someone use an old template to reuse the kit. I know the two side pieces would be gone (not attached).