Author Topic: 14 bolt SF vs. 14 bolt FF  (Read 7147 times)

Offline snibook7537

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14 bolt SF vs. 14 bolt FF
« on: March 06, 2012, 12:27:33 PM »
I might be buying an 1983 GMC k2500 with a 6.2 and a plow.  The truck is an 83 so it's got the semi float rear end. I have a rot box 87 v3500 thats just sitting around rotting more. My question is would it be worth it to swap the full floater to the 3/4 ton truck if the gears are the same? I think I remember reading somewhere that the spring perches are different on one tons and 3/4 tons, is that true?  Also am I actually going to really ever hurt the semi floater? I will mainly be plowing and scrapping stuff with it I occasionally put a real load on the 1 ton and I do occasionally do put a pretty heavy load when I'm scrapping but I kind don't know if it would be worth all the screwing around? I can't see myself doing any serious towing in the foreseeable future so maybe take that into account as well.   
Thanks
1984 Fiero se pwr windows Holley TBi, cam, 86 5spd
1987 GMC V3500 350 TBi 4spd 205 t-case

Shoulda never sold:
1976 c-10 beater 250-6 4spd no pwr steering, brakes. Recycling truck

Offline zieg85

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Re: 14 bolt SF vs. 14 bolt FF
« Reply #1 on: March 06, 2012, 03:32:48 PM »
Read through  http://forum.73-87chevytrucks.com/smforum/index.php/topic,23173.0.html  and see what Blazin thinks...

I thought the 83 K2500 with a diesel got the 14 bolt FF but maybe not.   If the 87 V3500 is not a cab and chassis the rear end should fit fine.
Carl 
1985 C20 Scottsdale 7.4L 4 speed 3.21
1986 C10 under construction
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Offline Jason S

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Re: 14 bolt SF vs. 14 bolt FF
« Reply #2 on: March 06, 2012, 05:54:05 PM »
I've personally seen the semi-float 14 bolts doing jobs that a Dana 80 really should be doing. Specifically, it was under a late 80's Chevy K2500 pulling a gooseneck trailer with 4 cords of green oak firewood - the guy delivering the wood had a few screws loose - definitely don't try this at home.

Of course it wouldn't hold up for over a few months under those conditions. So when the semi-float broke, he'd just put swap another rear end under the truck. 

The point is, the semi-float 14 bolt rear end he had under the truck held up for a remarkable amount of time considering the weight he was pulling and would probably do fine under your conditions. 

My $0.02: Run the semi-float until it breaks. If it doesn't break and you get tired of looking at a flat hub on the rear end, then swap in the full-float axle.

1973 GMC K2500, Super Custom, Camper Special, 350, TH350, NP203, 4.10's
1974 Chevrolet K10, Custom Deluxe, 350, SM465, NP203, 3.73's

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Offline bake74

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Re: 14 bolt SF vs. 14 bolt FF
« Reply #3 on: March 06, 2012, 06:47:24 PM »
     I am with Jason S on this one.  You don't sound like you need the FF on your truck unless you want the bragging rights.   ;D
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Offline snibook7537

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Re: 14 bolt SF vs. 14 bolt FF
« Reply #4 on: March 07, 2012, 11:50:41 AM »
Thanks guys thats kind of what I was thinking.  I don't really think it will break as I did a lot of stupid stuff with a 12 bolt in my c10 but this will see a lot more work so I wasn't sure.  Thanks to all of you who replied.
1984 Fiero se pwr windows Holley TBi, cam, 86 5spd
1987 GMC V3500 350 TBi 4spd 205 t-case

Shoulda never sold:
1976 c-10 beater 250-6 4spd no pwr steering, brakes. Recycling truck