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-   -   LWB to SWB conversion. where to make the rear frame cut? (https://67-72chevytrucks.com/vboard/showthread.php?t=398717)

SatisTraction 04-21-2010 10:35 PM

LWB to SWB conversion. where to make the rear frame cut?
 
today i took the plunge and cut 14" out of the frame to put the SWB bed on :metal: it looks good and did not take too long.

Now the question is where do i cut the rear of the frame and how much do i cut out?

thanks

73chevyman 04-21-2010 10:53 PM

Re: LWB to SWB conversion. where to make the rear frame cut?
 
right behind the cab and you cut 12" out the frame with 2 L cuts and a plate to go behind the cut

73chevyman 04-21-2010 11:04 PM

Re: LWB to SWB conversion. where to make the rear frame cut?
 
found this for ya might help but i would of cut it with 2 L cuts to make it stronger
http://www.73-87.com/7387garage/chas...lwb_to_swb.htm

glock35ipsc 04-21-2010 11:07 PM

Re: LWB to SWB conversion. where to make the rear frame cut?
 
14" out of the middle, and 6" straight of the rear.

Sounds like it's too late to make a good cut, but here is another reference on how to make the cut and shorten them.

http://67-72chevytrucks.com/vboard/s...d.php?t=123624

SatisTraction 04-21-2010 11:18 PM

Re: LWB to SWB conversion. where to make the rear frame cut?
 
that is how i cut and welded mine. 14" long with a 3" offset / dogleg.


i need to know where to cut the rear part of the frame. just 6" from the end or do i have to cut a section out and reweld it?

73chevyman 04-21-2010 11:21 PM

Re: LWB to SWB conversion. where to make the rear frame cut?
 
this is the type of cut i would of done
http://67-72chevytrucks.com/vboard/s...54#post3194654
sorry i'm just giving u ideas of what i was thinking

SatisTraction 04-21-2010 11:23 PM

Re: LWB to SWB conversion. where to make the rear frame cut?
 
Quote:

Originally Posted by 73chevyman (Post 3933978)
found this for ya might help but i would of cut it with 2 L cuts to make it stronger
http://www.73-87.com/7387garage/chas...lwb_to_swb.htm

thanks. looks liek 6" cut right off the rear should do it. i am going to hold off on that so i can tuck the bumper where i want it :lol:

SatisTraction 04-21-2010 11:26 PM

Re: LWB to SWB conversion. where to make the rear frame cut?
 
Quote:

Originally Posted by 73chevyman (Post 3934035)
this is the type of cut i would of done
http://67-72chevytrucks.com/vboard/s...54#post3194654
sorry i'm just giving u ideas of what i was thinking

that is the cut that i done. my doglegged part was not that long though.

73chevyman 04-21-2010 11:36 PM

Re: LWB to SWB conversion. where to make the rear frame cut?
 
wow glock thats a awesome faq what is was thinking

glock35ipsc 04-21-2010 11:42 PM

Re: LWB to SWB conversion. where to make the rear frame cut?
 
Thanks! That was my 68 I did about 5-6 years ago, but the principals are the same.

b454rat 04-22-2010 08:02 AM

Re: LWB to SWB conversion. where to make the rear frame cut?
 
I had 14" taken out of my frame, set the box in and it's damn near perfect. I need to cut the rear frame yet, so the box is sitting up in back. Looks like 5-6" should do it. I need to get my bumpers so I have some meat to bolt up to though, should be getting them in a week or so...

tx71smallblock 10-06-2014 09:57 PM

Re: LWB to SWB conversion. where to make the rear frame cut?
 
Gonna revive this one for a min, can this be done without complete removal of cab?

SkinnyG 10-06-2014 10:08 PM

Re: LWB to SWB conversion. where to make the rear frame cut?
 
Absolutely, man!

http://gwellwood.com/wordpress/wp-co...3s-480x358.jpg

http://gwellwood.com/wordpress/wp-co...29-480x360.jpg

Linky to mine: the-crusty-chevy/shortboxing-the-frame/

J Knight 10-06-2014 10:09 PM

Re: LWB to SWB conversion. where to make the rear frame cut?
 
Quote:

Originally Posted by tx71smallblock (Post 6869861)
Gonna revive this one for a min, can this be done without complete removal of cab?

On 73-87, yes.

tx71smallblock 10-07-2014 12:45 AM

Re: LWB to SWB conversion. where to make the rear frame cut?
 
So the cut location is too far under the cab on a 71 to be easy is what im guessing

Tervill 10-07-2014 12:52 PM

Re: LWB to SWB conversion. where to make the rear frame cut?
 
1 Attachment(s)
Quote:

Originally Posted by tx71smallblock (Post 6869861)
Gonna revive this one for a min, can this be done without complete removal of cab?

You bet it can. This is how I did mine...

tx71smallblock 10-07-2014 04:13 PM

Re: LWB to SWB conversion. where to make the rear frame cut?
 
But thats a square body isnt it?

SkinnyG 10-07-2014 11:32 PM

Re: LWB to SWB conversion. where to make the rear frame cut?
 
The original question was posted in the 73-87 section, so: yes.

I have seen 67-72's being cut under the cab. If it were me, I would yank the cab off.

Jonboy 10-08-2014 10:22 AM

Re: LWB to SWB conversion. where to make the rear frame cut?
 
I cut mine without removing the cab. Measured 1" back of the front set of bed bolts, then 14" back from that. Only had to drill out the rearmost set of bed mounting holes too.

Red Beard 10-10-2014 06:50 PM

Re: LWB to SWB conversion. where to make the rear frame cut?
 
What welding process are you guys using to do this?

SkinnyG 10-10-2014 08:47 PM

Re: LWB to SWB conversion. where to make the rear frame cut?
 
I used started using a Miller Diversion 180 TIG from work, but it wasn't happy with the metal, so I completed the job with a Millermatic 200 MIG. Stick also works. Ideally you will want at least 180A to get the best penetration.

That's just my opinion.

slimneverdies 10-12-2014 02:52 PM

Re: LWB to SWB conversion. where to make the rear frame cut?
 
Quote:

Originally Posted by SkinnyG (Post 6874563)
I used started using a Miller Diversion 180 TIG from work, but it wasn't happy with the metal, so I completed the job with a Millermatic 200 MIG. Stick also works. Ideally you will want at least 180A to get the best penetration.

That's just my opinion.

Exactly what do you mean the diversion 180 didn't like the metal???

SkinnyG 10-12-2014 03:26 PM

Re: LWB to SWB conversion. where to make the rear frame cut?
 
TIG needs really, really clean metal. Despite grinding the surface nice and shiny, I ended up with some kind of impurity or something fizzling and getting on the tung. I gave up and just went MIG. It could be rust that was still in the metal, it could even have been a faulty tank of Argon. I gave up and went MIG.

slimneverdies 10-12-2014 03:53 PM

Re: LWB to SWB conversion. where to make the rear frame cut?
 
Quote:

Originally Posted by SkinnyG (Post 6876373)
TIG needs really, really clean metal. Despite grinding the surface nice and shiny, I ended up with some kind of impurity or something fizzling and getting on the tung. I gave up and just went MIG. It could be rust that was still in the metal, it could even have been a faulty tank of Argon. I gave up and went MIG.

Ok. I was making sure you didn't mean it didn't have enough mustard to do the job on 1/8 steel. I'm about to buy one soon to take around for little odd jobs cause the 210 syncrowave is too damn heavy....

SkinnyG 10-12-2014 11:30 PM

Re: LWB to SWB conversion. where to make the rear frame cut?
 
I teach high school metalwork. I had the school buy a Diversion 180 and it's a very decent machine. It doesn't have a lot of options, though, so you ~may~ out grow it.


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