14-bolt installation question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

4x4 Pray · 12-11-2002, 07:33 PM

I just picked up a free 14-bolt with a locker out of a '78 1 ton chevy. I have a 3/4 ton '70 4x4 with an eaton in it right now. Does anyone know anything about doing this swap? Anyone relocated spring perches before? Sounds like a major pain to me. Also, will the overall width of the axles be the same?

Any advice is welcome. I was excited, but now I'm nervous that I got more work than I bargained for.

Jeff

ozarkhippie · 12-11-2002, 07:40 PM

measure the distance from center to center of the spring perches of each axle. If the 14 bolt came out of a 1 ton it should be the same as the one in your 70, so there should not be any spring perch relocation.

Alexis · 12-11-2002, 07:41 PM

.............hehe your in for some fun. i just finished doin this swap in my 3/4 ton.Things your going to need are the brake brass fitting 3/16 female to 1/4 male(real pain to find so i incountered). Oh and the U-joint strap kit i used was "360-10" napa.

Alexis · 12-11-2002, 07:59 PM

14-bolt FF 4.56 posi

Alexis · 12-11-2002, 08:00 PM

kinda blurry cause i used the program to zoom

4x4 Pray · 12-11-2002, 09:00 PM

thanks for the tips. went and measured my perches and the new perches. mine are about 2.5" narrower. guess the 14 bolt is from a 3/4 ton then.

thanks for the pics too. you looking good. mines covered in rust.

**jerry moss** · 12-11-2002, 09:35 PM

i've done this swap on a few trucks, it takes some time but is well worth the effort. you can buy new spring pads at most speed shops, i use a 4inch grinder to cut off the old pads. grind off and re-use the shock mounts (they're staggered on the 79). you'll need an angle guage to set pinion angle, brake line fittings and longer e-brake cables. i get my e-brake cables redone at nevada speedometer in reno nevada. if you have any questions, feel free to call me, 925-634-2512.

4x4 Pray · 12-11-2002, 10:45 PM

925? WOW, you live right by me! I go to school in San Luis Obispo, but my hometown is in Clayton (right by Concord). That's pretty cool.

Anyway, I appreciate the encouragement. You have inspired me to keep on going on this project. But what's an angle guage look like? And can I set the angle some other way rather than buying the guage? Will it screw things up if just I try to get it as close as I can?

roger0080 · 12-11-2002, 11:20 PM

I've done this to my 71 K20 also.

I'ld rather have the Eaton myself and just pay for the NoSpin diff if you want a locker that bad. You can get a disk brake conversion kit for the Eaton rear end too! Check out: http://members.aol.com/blackbirdstrucks/index4.html

But what I did as others said is you will have to move the spring perches in. I had a shop do mine.
Relocate the shock brackets on the axle, my pinion strap to the yoke and U-joint fit right into the 14-bolt, did a brake job on the 14-bolt since you have it out. The Eaton uses 5/16" brake line to the wheel cylinders where the 14-bolt will use 3/16". No problem. I bought new wheel cylinders for the Eaton and bolted them into the 14-bolt. Ran new 5/16" line from the wheel cylinders to the "T" connection. No fuss no mess.

Hardest part is getting the right pinion angle when it's all done. I had to use some tapered shims and it was pretty close.

-Roger

12-11-2002, 07:33 PM	#1
4x4 Pray Registered User Join Date: Apr 2001 Location: San Luis Obispo, CA Posts: 69	14-bolt installation question I just picked up a free 14-bolt with a locker out of a '78 1 ton chevy. I have a 3/4 ton '70 4x4 with an eaton in it right now. Does anyone know anything about doing this swap? Anyone relocated spring perches before? Sounds like a major pain to me. Also, will the overall width of the axles be the same? Any advice is welcome. I was excited, but now I'm nervous that I got more work than I bargained for. Jeff

12-11-2002, 07:41 PM	#3
Alexis Member since 2000 Join Date: Dec 2000 Location: Mountain View Ca / Mexico Posts: 7,879	.............hehe your in for some fun. i just finished doin this swap in my 3/4 ton.Things your going to need are the brake brass fitting 3/16 female to 1/4 male(real pain to find so i incountered). Oh and the U-joint strap kit i used was "360-10" napa. Last edited by Alexis; 12-11-2002 at 07:58 PM.

12-11-2002, 07:59 PM	#4
Alexis Member since 2000 Join Date: Dec 2000 Location: Mountain View Ca / Mexico Posts: 7,879	hers a picture 14-bolt FF 4.56 posi Attached Images

12-11-2002, 08:00 PM	#5
Alexis Member since 2000 Join Date: Dec 2000 Location: Mountain View Ca / Mexico Posts: 7,879	picture of the fittings kinda blurry cause i used the program to zoom Attached Images

12-11-2002, 09:35 PM	#7
jerry moss Born Psycho Join Date: Feb 2001 Location: brentwood,cal,usa Posts: 4,742	i've done this swap on a few trucks, it takes some time but is well worth the effort. you can buy new spring pads at most speed shops, i use a 4inch grinder to cut off the old pads. grind off and re-use the shock mounts (they're staggered on the 79). you'll need an angle guage to set pinion angle, brake line fittings and longer e-brake cables. i get my e-brake cables redone at nevada speedometer in reno nevada. if you have any questions, feel free to call me, 925-634-2512. __________________ jerry moss 72 cheyenne super K20- tilt,tach,vacuum,speedwarning,buckets,shoulder belts,am/fm,tow hooks,bumper guards,toolbox,aux. fuel tank,posi front and rear,plus other goodies!!! SOLD 69 suburban K20-tilt,tach,vacuum,speedwarning,buckets,shoulder belts,am/fm,4 inch all spring lift,4 speed, 14 bolt full floater, dana 44 HD,warn winch,posi front and rear,tow hooks,plus other goodies. 73/80 chevy/gmc K20 SB400,turbo 400,205,tilt,a-c,gas hog. 77 K/5 cheyenne blazer-daily driver/beater. SON HAS IT NOW BRENTWOOD,CALIFORNIA

12-11-2002, 07:40 PM	#2
ozarkhippie Registered User Join Date: Nov 2002 Location: Eureka Springs AR Posts: 494	measure the distance from center to center of the spring perches of each axle. If the 14 bolt came out of a 1 ton it should be the same as the one in your 70, so there should not be any spring perch relocation.

12-11-2002, 09:00 PM	#6
4x4 Pray Registered User Join Date: Apr 2001 Location: San Luis Obispo, CA Posts: 69	thanks for the tips. went and measured my perches and the new perches. mine are about 2.5" narrower. guess the 14 bolt is from a 3/4 ton then. thanks for the pics too. you looking good. mines covered in rust.

12-11-2002, 10:45 PM	#8
4x4 Pray Registered User Join Date: Apr 2001 Location: San Luis Obispo, CA Posts: 69	925? WOW, you live right by me! I go to school in San Luis Obispo, but my hometown is in Clayton (right by Concord). That's pretty cool. Anyway, I appreciate the encouragement. You have inspired me to keep on going on this project. But what's an angle guage look like? And can I set the angle some other way rather than buying the guage? Will it screw things up if just I try to get it as close as I can?

12-11-2002, 11:20 PM	#9
roger0080 Registered User Join Date: Nov 2000 Location: Carver County, Minnesota, USA Posts: 626	I've done this to my 71 K20 also. I'ld rather have the Eaton myself and just pay for the NoSpin diff if you want a locker that bad. You can get a disk brake conversion kit for the Eaton rear end too! Check out: http://members.aol.com/blackbirdstrucks/index4.html But what I did as others said is you will have to move the spring perches in. I had a shop do mine. Relocate the shock brackets on the axle, my pinion strap to the yoke and U-joint fit right into the 14-bolt, did a brake job on the 14-bolt since you have it out. The Eaton uses 5/16" brake line to the wheel cylinders where the 14-bolt will use 3/16". No problem. I bought new wheel cylinders for the Eaton and bolted them into the 14-bolt. Ran new 5/16" line from the wheel cylinders to the "T" connection. No fuss no mess. Hardest part is getting the right pinion angle when it's all done. I had to use some tapered shims and it was pretty close. -Roger __________________ 72 Chev C-10 90% restored (former AZ truck) ... 71 Chev K-20 Cheyenne my vacation crusier... 72 Chev C-10 Now retired and striped after many faithful miles... 72 GMC 1500 Retired to the junk yard after bought new in '71...



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