Swapping from 14B semi-float to 14B full float

[86454k30]

Here is what I can share with you on the SF to FF conversion as I did it on a 86 K20

73-83 14 bolt FF have park brake cables that run up both LH and RH frame
84-91(squarebody) 14 bolt FF have one long and one short park brake cable and run up the driver side frame rail
Backing plates are not the same but are interchangeable
You can't interchange the short/short and short/long brake cable backing plates they are different, short/short cables bolt to the backing plate and short/long snap in.
14SF to 14FF center of tube to center of ujoint cap is 1.5" shorter on FF than on the SF which means I had to lengthen my rear drive shaft
Ujoints were the same

 

[SirRobyn0]

So other than the before mentioned parking brake cables does anyone know of any other issues putting FF diff out of a 77 C30 into a 84 C20? I've got one I'm looking at. Thanks.

 

[SirRobyn0]

Ok so the one I was considering yesterday is beyond what I wanna mess with. Now I've got a possible unit out of CCUV. IDK much about the CCUV's are the 14B 10.5's the same or will I be needing to modify? The CCUV unit I'm looking at has 4.56 gears in it so that is very much appealing. I need to find out what if anything it might have for locker / posi. or if it's open. IDK if gov locks went into those things....

 

[Bextreme04]

Ok so the one I was considering yesterday is beyond what I wanna mess with. Now I've got a possible unit out of CCUV. IDK much about the CCUV's are the 14B 10.5's the same or will I be needing to modify? The CCUV unit I'm looking at has 4.56 gears in it so that is very much appealing. I need to find out what if anything it might have for locker / posi. or if it's open. IDK if gov locks went into those things....

A CUCV axle will have a detroit locker in it. I believe it will also share the same parking brake arrangement as your 84.

 

[SirRobyn0]

A CUCV axle will have a detroit locker in it. I believe it will also share the same parking brake arrangement as your 84.

Ok cool on the parking brake cable thing, not sure on the locker, do the Detroit's have good enough manors for the street?

 

[Bextreme04]

Ok cool on the parking brake cable thing, not sure on the locker, do the Detroit's have good enough manors for the street?

I dont have personal experience. Mine has the grizzly locker and there is some definite binding and clicking on sharp corners. Actual driving seems unaffected though.

 

[SirRobyn0]

I dont have personal experience. Mine has the grizzly locker and there is some definite binding and clicking on sharp corners. Actual driving seems unaffected though.

Ok well I'm going to hopefully talk to the guy with the axle this weekend and we'll see what if anything comes of it. Thanks.

 

[Craig 85]

FYI C/K 30 axles have the shock mounts reversed from your C20 and the spring perches are closer to the frame due to the narrower spring mounts. CCUV is basically a K30 with some minor differences. As said before, going from a SF 14 bolt to a FF 14 bolt you will need to lengthen the driveshaft.

Here's my K30 SRW with a 14 bolt FF for reference.

You must be registered for see images attach

 

[Bextreme04]

I did see a guy in Sultan that has a 14BFF from a 1974 K20 for $250. Its got 4.10's though and would have the early parking brake style. I forgot that the 30's had a different shock orientation

 

[SirRobyn0]

I did see a guy in Sultan that has a 14BFF from a 1974 K20 for $250. Its got 4.10's though and would have the early parking brake style. I forgot that the 30's had a different shock orientation

That's got to be John. I'll reach out to him again. Last time I talked to him the one he had, had been modified in ways I wasn't thrilled with. I see 4.10 and 4.56 as both having benefits and detractions. I'd be fine with either I think.

 

[SirRobyn0]

FYI C/K 30 axles have the shock mounts reversed from your C20 and the spring perches are closer to the frame due to the narrower spring mounts. CCUV is basically a K30 with some minor differences. As said before, going from a SF 14 bolt to a FF 14 bolt you will need to lengthen the driveshaft.

Here's my K30 SRW with a 14 bolt FF for reference.

You must be registered for see images attach

Thanks for the picture IDK on the driveshaft thing. I've heard folks say that and others that say it's not enough of a difference. I think for me it would be before and after measurements and going from there. Thanks again.

 

[Bextreme04]

That's got to be John. I'll reach out to him again. Last time I talked to him the one he had, had been modified in ways I wasn't thrilled with. I see 4.10 and 4.56 as both having benefits and detractions. I'd be fine with either I think.

No, its not John. Its a guy named Kenny. I'll get you his contact info if you want to contact him.

 

[shiftpro]

Regarding Gov Lock....
My perspective is within 4x4 off road technical crawling.
Never... stay away from it.
In your case... maybe it's totally fine. I always found them to be more of a winter back alley escape tool and that's about it.

 

[SirRobyn0]

No, its not John. Its a guy named Kenny. I'll get you his contact info if you want to contact him.

Oh right, I've heard of Kenny but never spoken to him. When you can his info would be great, thanks.

 

[SirRobyn0]

Regarding Gov Lock....
My perspective is within 4x4 off road technical crawling.
Never... stay away from it.
In your case... maybe it's totally fine. I always found them to be more of a winter back alley escape tool and that's about it.

I had a farmer friend with 72 C30, about 25 years ago with a Gov Lock in it, and I logged more than a few miles in it. There were a few instances where I think it was helpful. We never blew it up, and at the time did not know it's down falls, but just drove the truck without thinking about it really.

My truck sees mostly on road use, but it does go out to the bird pens on my place and into my dad's fields at his place. Neither are flat. I've never had the truck stuck at either place beyond loosing traction and having to back up or pull forward a little before resuming. I do a fair bit of towing and when I have to turn the trailer around in grass or drive out into a hay field, a gov lock might be helpful. In the end I think, I'm fine with an open diff or a gov lock, provided that it is in good shape when I receive the axle. I think I'd be fine with a Detroit if I end up with a CCUV axle provided that their on road manners aren't to bad.