Short Bed on Crew Cab 1 ton frame issue - The 1947 - Present Chevrolet & GMC Truck Message Board Network

DBear · 12-20-2017, 02:04 AM

Hey guys...just finished shortening my 78 K30 Crew frame for a short bed conversion. Everything looks great....Except, the bed sits low on the rear of the frame, but sits at the right level in the front next to the cab. To get it level, the rear has to be raised right at 1 inch at the furthest rear mounting hole. I doubled checked and checked again my frame conversion and everything is square and level. The bed came off of a 84 or so shortbed 2 wheel drive. I measured the bed mounting flanges underneath the 2 beds, and the 78 k30's were just at a 1/4" taller than the 84 c10's. There still is about 3/4 of an inch unaccounted for. My only other guess would be the rear frame sections are taller on the 1/2 ton trucks vs. the 1 ton 4x4s?? Anyone else have this problem or are in the know of this situation?? Thanks in advance.

v30crewcab · 12-24-2017, 02:02 PM

mine went together no problem. you sure you don't need to raise the back of the frame up a touch?

sweetk30 · 12-24-2017, 04:42 PM

rear hump arch back is all the same .

1tons have taller frame in the long middle sections . under the cab and some of the box area . but the extra is on the bottom side of the frame .

wildwilly4x4 · 12-24-2017, 10:06 PM

ive shortened a bunch of these, and never had this issue.. Positive the frame is right?

**1774btcrew** · 12-26-2017, 01:24 AM

It can be an optical illusion as well. The body line seems to slop rearward and is more noticeable on a crew cab. Mine appeared that way too. Frame was cut within 1/16" from side to side and cut straight. I have noticed this illusion on other shortbed crewcabs too.

RADustin · 12-27-2017, 09:51 AM

I leveled my frame, as best I could. Keeping in mind the factory stampings aren't perfect.

Then I clamped thick plate off of each bed mount that hung over the side of the frame and used a long level to ensure all of the bed mounts were flat with each other. I did this before and after I cut it to make sure the factory frame wasn't whacked.

I'd check to make sure you are checking flatness over a long distance and not just within the cut area. If the frame is flat, and the bed mounts are all the same height, maybe your cab is leaning one way or the other??

12-20-2017, 02:04 AM	#1
DBear Registered User Join Date: Nov 2008 Location: Rowlett, TX Posts: 863	Short Bed on Crew Cab 1 ton frame issue Hey guys...just finished shortening my 78 K30 Crew frame for a short bed conversion. Everything looks great....Except, the bed sits low on the rear of the frame, but sits at the right level in the front next to the cab. To get it level, the rear has to be raised right at 1 inch at the furthest rear mounting hole. I doubled checked and checked again my frame conversion and everything is square and level. The bed came off of a 84 or so shortbed 2 wheel drive. I measured the bed mounting flanges underneath the 2 beds, and the 78 k30's were just at a 1/4" taller than the 84 c10's. There still is about 3/4 of an inch unaccounted for. My only other guess would be the rear frame sections are taller on the 1/2 ton trucks vs. the 1 ton 4x4s?? Anyone else have this problem or are in the know of this situation?? Thanks in advance.

12-24-2017, 02:02 PM	#2
v30crewcab Registered User Join Date: Apr 2012 Location: Chatt Tn Posts: 966	Re: Short Bed on Crew Cab 1 ton frame issue mine went together no problem. you sure you don't need to raise the back of the frame up a touch? __________________ 88 military v30 crewcab shortbed 5.9 cummins, nv4500, 205 86 k30, 89 diesel burb, 76 gmc pathfinder 71 longbed 5.3 4l80 http://67-72chevytrucks.com/vboard/s...d.php?t=522535

12-24-2017, 04:42 PM	#3
sweetk30 Registered User Join Date: May 2012 Location: horseheads,ny rust belt Posts: 2,794	Re: Short Bed on Crew Cab 1 ton frame issue rear hump arch back is all the same . 1tons have taller frame in the long middle sections . under the cab and some of the box area . but the extra is on the bottom side of the frame . __________________ 77-k30lb BIG truck build . 87-k30lb budget beater build . 85-k30lb the plow machine build . 85-c10sb summer fun toy . ----------------------------- HOLLEY SNIPER efi = worst case of p.i.t.a i ever had . EDELBROCK pro flo 4 = best deal going so far . love my setup works great.

12-24-2017, 10:06 PM	#4
wildwilly4x4 Registered User Join Date: Aug 2009 Location: Sunray,TX Posts: 251	Re: Short Bed on Crew Cab 1 ton frame issue ive shortened a bunch of these, and never had this issue.. Positive the frame is right?

12-26-2017, 01:24 AM	#5
1774btcrew Senior Member Join Date: Jun 2009 Location: Phoenix AZ Posts: 4,557	Re: Short Bed on Crew Cab 1 ton frame issue It can be an optical illusion as well. The body line seems to slop rearward and is more noticeable on a crew cab. Mine appeared that way too. Frame was cut within 1/16" from side to side and cut straight. I have noticed this illusion on other shortbed crewcabs too. __________________ AZPartsLocators on Instagram 1972 Cheyenne Super Short Bed big block "Blackie" 1977 Crew Cab GMC Short bed with 4BT Intercooled Cummins Diesel and a 4L80e "The Junkyard Dog" 1985 Crew Cab Chevy dually with 5.9 Cummins "The Big Dog" This is what my dad liked to be called by the grandkids before he passed so it seems fitting for his old truck.

12-27-2017, 09:51 AM	#6
RADustin Registered User Join Date: Jun 2017 Location: New Orleans Posts: 386	Re: Short Bed on Crew Cab 1 ton frame issue I leveled my frame, as best I could. Keeping in mind the factory stampings aren't perfect. Then I clamped thick plate off of each bed mount that hung over the side of the frame and used a long level to ensure all of the bed mounts were flat with each other. I did this before and after I cut it to make sure the factory frame wasn't whacked. I'd check to make sure you are checking flatness over a long distance and not just within the cut area. If the frame is flat, and the bed mounts are all the same height, maybe your cab is leaning one way or the other??



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