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  #1  
Old 05-28-2004, 10:47 AM
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Default What\'s a Heavy Half?

I was told my truck was a heavy half. What exactly does that mean and how do you tell? It's a 1988 K1500, 350/700?
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  #2  
Old 05-28-2004, 11:26 AM
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Default Re: What\'s a Heavy Half?

as far as I know it has to do with the rear end being the semi floating 14 bolt, and maybe heavier GVWR and GCVWR. The GM options packages get really confusing. Z71 does not mean the same options on all trucks, and the towing package may be part of the heavy half designation, but it's also available separately. Hopefully someone else will have more defined answers.
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Old 05-28-2004, 06:35 PM
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Default Re: What\'s a Heavy Half?

i want to say with the heavy halfs, that they are a higher GVWR. which means that its just like a light 3/4. i think they have a 12 bolt SF [still the six lug pattern]. because the 'regular' 3/4 [eight lug, also the 'heavy' 3/4 too i believe] use a 14 bolt SF or FF so in reality instead of being a 1/2 ton or a 3/4 ton, its a 5/8 ton. that's where the 'heavy' comes in.
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Old 05-28-2004, 06:42 PM
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Default Re: What\'s a Heavy Half?

I agree with you both above. My 96 is a heavy half ton. Its got comparable leaf springs to the 3/4 ton and does have the 14b SF in the rear. Checking the RPO codes in the glove box will give all the options that came with the truck. I forget what my GVWR is but it is a couple of steps up from the standard 1/2 ton, somewhere around 8500 lbs. I also believe the frame is reinforced more than a standard 1/2 ton. I've never had a chance to compare the frames though so I may be way off-base.
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Old 05-28-2004, 07:39 PM
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Default Re: What\'s a Heavy Half?

If it's anything like my '98, the dealer will call it a "3/4 ton". 14 bolt SF rear.

6600 GVWR, which I think it only 200-400 lbs more than a comparable "regular" half-ton. more often than not though they still have the 4L60E vs. the heavier-duty 4L80E.

Also it has these RPO codes, YMMV:

f44 Chassis, Heavy Duty
gt4 Rear Axle: 3.73 Ratio
g80 Rear Axle: Positraction
jb6 Brake System: Power, Front Disc, Rear Drum, 7200 Lbs.
knp Transmission, Heavy Duty Cooling System
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Old 05-28-2004, 09:11 PM
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Default Re: What\'s a Heavy Half?

my '93 K1500 has a GVWR of 6100lbs. the gear ratio shouldn't play that big of a deal in with it. all that was options. i think 3.42's came stock, and the 3.73's and 4.10's were the options. a tow package shouldn't really matter if its 'regular' or 'heavy', because if it did, then all the 1/2 tons are made 'heavy' buy putting one on them.
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Old 05-30-2004, 10:18 AM
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Default Re: What\'s a Heavy Half?

F44 is the code that gives you the 14SF 9.5" rear end in a half ton.

"Heavy Half" was a nickname for the late 70's "half tons" that were actually 3/4 tons with 8 lug D44's and 14FF's. Friend of mine has a 78. Everything but the axles was standard half ton stuff. It was a way to get around the still new and incomplete emissions laws of the time.

88 on there was only one "Heavy Half" but it was not called that. The 2500LD was basically a regular 1500 with the same engine, trans, front axle, and frame as a 1500, only it came with stiffer torsion bars, higher spring rate leaf springs, and a 6 lug 14SF. GVWR was up some from the 1500's but not the same as a standard 2500 3/4 ton with 8 lugs. This is what The Kid's truck is. This is why when you look at lift kits some of the 1500/6 lug kits also specify "6 lug 3/4 tons".

Then there were the F44 option which got you the 14SF rear end and stiffer torsion bars and higher rate leaf springs. GVWR was more than the regular 1500's, but not higher than the 2500LD. What else it contained is not really known, but it's kinda spotty on how and when it was used. Some 1500 trucks all set up for heavy duty towing and camper packages came with the regular weak ass 10bolt. Other 1500 trucks with no special options, low GVWR, and not even a hitch from the factory came with 14SF's......but rarely. If you have a regular 1500 with a 14SF congrats, you won the lottery.

NO, there is NO frame difference in either of these trucks. It's the exact same frame as the lowest GVWR 2wd V6 and a stick 1500 had. Sorry to burst your bubble.

The 12 bolt went the way of the dodo in about 1980 but GM used the last of their reserves into the early 80's. However NO 12 bolts went under any IFS trucks from the factory.
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Old 05-30-2004, 12:01 PM
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Default Re: What\'s a Heavy Half?

guys, i have to disagree with yall and the F44 option being the 14sf. the parts truck i have right now has the F44 option and it does not have the 14sf. it had a 10 bolt with 3.73s.

the F44 option just says "chassis, heavy duty"
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Old 05-30-2004, 12:34 PM
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Default Re: What\'s a Heavy Half?

Shhhhhush woman, not in front of the kids! Kidding, kidding........ [img]images/graemlins/wink.gif[/img]

Seriously though, I think the F44 package has something to do with it. Did a little post archaeology here:
http://bbs.off-road.com/ubbthreads/s...rue#Post972979
and for some REALLY old digging:
http://bbs.off-road.com/ubbthreads/s...rue#Post439141
[img]images/graemlins/cool.gif[/img] Jeesh, I was still in the Marines in San Diego then. Makes me feel old. [img]images/graemlins/tongue.gif[/img]

Hmmm, maybe you guys who have trucks with the 14SF's from the factory need to look for code Y06?
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Old 05-30-2004, 01:31 PM
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Default Re: What\'s a Heavy Half?

in the 70's i think it was just springs...had a friend with one...actually a big 10, but i think it was the same thing, and it was a 1/2 ton with heavier springs...then on the newer ones ive seen had 3/4 ton axles, but only 6 lug
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