14 bolt ff swap tips

[Recon 78]

Cucv 14 bolt swap into 78 k5
Lots of info out there on perch width, setting pinion angle, etc.

Looking for tips on how to set up and be able to move axle side to side for centering. Jack stand placement, how to remove vehicle weight so axle can move, etc

This is a driveway swap,body on.
Also shackle is stock so when you lower axle there's massive droop
How do you deal with that?

Any ideas/tips appreciated

Recon

 

[Scribbles]

I want to know many of the same questions.

 

[Fastereddie]

The best investment not only for safety but ease of doing the stuff we do... 10 ton jack stands from sunnex



Sunex 1410 10-Ton, High Height, Pin Type, Jack Stands, Pair https://www.amazon.com/dp/B0093NBRHA/ref=cm_sw_r_cp_api_i_RZmzFbSEJHR2P

 

[Recon 78]

Damn
Those are sexy as hell

Gonna b using 12 ton hf stands
They've worked ok so far

 

[yblow]

I bought diy4x jack saddle , it's well worth the money for these swaps. I had to adapt it to my jack.

https://diy4x.com/product.php?productid=17760

I also use those sunnex jack stands above.

 

[TreeFarm]

Here is how I do it, this may not be the most accurate but Ive done it a number of times. Start with supporting the vehicle by the frame and removing your old axle

Clean the axle, remove the spring perches and everything else you don't need. I "Install" The axle with the new spring perches and u bolts just sitting on there loosely. Think finger tight, Just enough so there isn't a gap between the axle and spring. Now the axle is installed hanging by the ubolts on the springs. Use a jack under the pinon to hold it up roughly in the right spot. Measure from the spring perches or spring center pins to the brake mounts at the end of the axle tube. You want this measurement to be equal side to side to center the axle under the truck. Its important to be sure that the springs aren't bound up or pushed to one side or the other. So as you adjust the axle side to side, recheck center pin distance on the two springs and all that jazz. Once the axle is centered, tighten up the u bolts a bit. This will hold the axle in place with friction. I then pick up the truck by the axle and put jack stands under the axle tubes. Now the weight is resting on the axle and suspension. Now you can use a jack under the pinion to set the pinion angle. Make sure when you are measuring pinion angle that you are using a flat surface either parallel or perpendicular to the pinion shaft. So the flats that the u bolt straps bolt to, The pinion carrier mount on the 14b, the surface that the diff cover bolts to, or I believe there is a rip parallel to the pinion on the 14b. You may need to loosen up the u bolts a bit to be able to rotate the axle to adjust. Once your pinion angle is set, and you re check your side to side measurements. Tack the perches in, pull the axle, and weld it up.

Here is a picture for reference. This is in a GMT400 so the springs/perches are way closer to the ends of the axle tubes then on a square body.

 

[yblow]

One thing you might want to check for is after you tack would be to lower axle to jack stands on level ground and with a digital angle finder place on the top perches to make sure there at the same angle on the tube. If you now the pinion angle you want and the angle of the perches as they rest on the leafs before you remove the old axle you can set up with a couple angle finders and center the perches on the tube with correct spacing. Tack and than check for fitment then weld on.

 

[Recon 78]

Awesome tips guys, thanks
Exactly the stuff I'm looking for

Keep them coming

 

[Recon 78]

Axle is bolted in rite now but not welded.

Had to get it out of garage but couldn't burn it in till i swapped the 203 for a 205 so i would know pinion angle

Stock shackle allows so much droop you almost run out of clearance

I knew guys here would have tips to get er done

 

[Recon 78]

And that jack saddle looks f#@$ing
Awesome

 

[Recon 78]

Got er done
Tips made it pretty simple

Axle on ubolts at full droop, i loosened u bolts to lower perch a 16th away from spring

Jack under pumkin and i could move axle side to side to center

Tighten up, back on jacks stands, jack up pinion to proper angle, tighten u bolts, booger tack perches

Done. All i have to do is hire a real welder to burn them in

Thanks again guys