Shortening A Longbed 50 Frame To Shortbed - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Fat Mike · 05-21-2010, 05:40 PM

Where is the best place to take out the 9.25" on a longbed 50 frame? My concern is the rear running board brackets. Please post pictures.
Thanx in advance.

T Hilde · 05-21-2010, 07:22 PM

was looking at mine to do the same. behind the cab and before the e-brake brackets.

yoder · 05-21-2010, 07:22 PM

Youll have to change or modify the rear bracket anyway cause its different from a long to shortbox. I cut mine right behind the cab.

Fat Mike · 05-22-2010, 12:12 AM

Do you have pictures?

mr48chev · 05-22-2010, 01:21 PM

This is the frame that is going under the truck I am stretching the cab on.

The extra front crossmember (this is a GMC 1/2 ton frame) is where the added length is.

I'd shorten one in that area just in front of the crossmember with the gussets on it.
And I would overlap it per one of the board members diagrams from another thread.

Note that the measurements are off for the AD trucks though and I think the difference in length is 9-1/4 inches but it may be 9-1/2. The overlap gives a lot more strength than a but welded frame would. I'd still box it or plate it in that area though.

I'm pretty sure you are going to have to relocate the center running board bracket too but don't have the boards off the 48 to measure the difference at the moment. If you were closer I'd swap you a pair of nice short bed running boards for a decent set of longbed running boards.

Fat Mike · 05-22-2010, 03:20 PM

The truck I have was suppose to have longbed running boards, but they cut them and put a longbed 54-59 truckbed on it. Sorry about that. Thanks for the information.

Dan Bowles · 05-22-2010, 10:06 PM

Do you have a LONG bed 1 ton or a long bed 3/4 ton? There is a big difference! 137 ish" wheelbase on the 1 ton, so you'll be taking 21" out not 9 or 10"!!

Dan Bowles · 05-22-2010, 10:07 PM

Oh yeah, I'd also make the wheelbase 117.5" so you put the rear wheels centered in the opening. The frame is also a bit different at the rear, post axle.

Fat Mike · 05-22-2010, 11:46 PM

Quote:

Originally Posted by Dan Bowles

Do you have a LONG bed 1 ton or a long bed 3/4 ton? There is a big difference! 137 ish" wheelbase on the 1 ton, so you'll be taking 21" out not 9 or 10"!!

It is a longbed 3/4 ton 50 gmc truck.

05-21-2010, 05:40 PM	#1
Fat Mike Registered User Join Date: Sep 2009 Location: Albuquerque, NM Posts: 540	Shortening A Longbed 50 Frame To Shortbed Where is the best place to take out the 9.25" on a longbed 50 frame? My concern is the rear running board brackets. Please post pictures. Thanx in advance. __________________ FAT MIKE My 59 http://67-72chevytrucks.com/vboard/s...d.php?t=400201 My 47 http://67-72chevytrucks.com/vboard/s...d.php?t=386848

05-21-2010, 07:22 PM	#2
T Hilde Registered User Join Date: Apr 2009 Location: Faribault, MN Posts: 385	Re: Shortening A Longbed 50 Frame To Shortbed was looking at mine to do the same. behind the cab and before the e-brake brackets.

05-21-2010, 07:22 PM	#3
yoder Registered User Join Date: Nov 2009 Location: west salem wi Posts: 8	Re: Shortening A Longbed 50 Frame To Shortbed Youll have to change or modify the rear bracket anyway cause its different from a long to shortbox. I cut mine right behind the cab.

05-22-2010, 12:12 AM	#4
Fat Mike Registered User Join Date: Sep 2009 Location: Albuquerque, NM Posts: 540	Re: Shortening A Longbed 50 Frame To Shortbed Do you have pictures? __________________ FAT MIKE My 59 http://67-72chevytrucks.com/vboard/s...d.php?t=400201 My 47 http://67-72chevytrucks.com/vboard/s...d.php?t=386848

05-22-2010, 01:21 PM	#5
mr48chev Registered User Join Date: Jul 2007 Location: Toppenish, WA Posts: 15,307	Re: Shortening A Longbed 50 Frame To Shortbed This is the frame that is going under the truck I am stretching the cab on. The extra front crossmember (this is a GMC 1/2 ton frame) is where the added length is. I'd shorten one in that area just in front of the crossmember with the gussets on it. And I would overlap it per one of the board members diagrams from another thread. Note that the measurements are off for the AD trucks though and I think the difference in length is 9-1/4 inches but it may be 9-1/2. The overlap gives a lot more strength than a but welded frame would. I'd still box it or plate it in that area though. I'm pretty sure you are going to have to relocate the center running board bracket too but don't have the boards off the 48 to measure the difference at the moment. If you were closer I'd swap you a pair of nice short bed running boards for a decent set of longbed running boards. Last edited by mr48chev; 05-22-2010 at 01:24 PM.

05-22-2010, 03:20 PM	#6
Fat Mike Registered User Join Date: Sep 2009 Location: Albuquerque, NM Posts: 540	Re: Shortening A Longbed 50 Frame To Shortbed The truck I have was suppose to have longbed running boards, but they cut them and put a longbed 54-59 truckbed on it. Sorry about that. Thanks for the information. __________________ FAT MIKE My 59 http://67-72chevytrucks.com/vboard/s...d.php?t=400201 My 47 http://67-72chevytrucks.com/vboard/s...d.php?t=386848

05-22-2010, 10:06 PM	#7
Dan Bowles AD Addict Join Date: Oct 2009 Location: Blissfield, MI Posts: 822	Re: Shortening A Longbed 50 Frame To Shortbed Do you have a LONG bed 1 ton or a long bed 3/4 ton? There is a big difference! 137 ish" wheelbase on the 1 ton, so you'll be taking 21" out not 9 or 10"!!

05-22-2010, 10:07 PM	#8
Dan Bowles AD Addict Join Date: Oct 2009 Location: Blissfield, MI Posts: 822	Re: Shortening A Longbed 50 Frame To Shortbed Oh yeah, I'd also make the wheelbase 117.5" so you put the rear wheels centered in the opening. The frame is also a bit different at the rear, post axle.



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