Re: 1971 K20- project just get driveable!!
 

you dont want to limit the ability of the suspension to droop. with only three inches of downtravel in the shock you will be mechanically limiting it with the shock. that can make for a poor ride and may damage the shock. you also dont want to limit the suspension uptravel with the shock, but if you have a little more shock travel than distance to the snubber you should be good. it sounds like you dont have that.

as for the ubolts, i always make em as tight as i can with an end wrench. then check at 500 miles. and again the next time after that you remember. they will loosen.

Re: 1971 K20- project just get driveable!!
 

Per the U-bolts i can get the torque later tonight when i get home from work if nobody chimes in.. But if you have time try searching in this thread for a PDF copy of the service manual.

http://67-72chevytrucks.com/vboard/s...d.php?t=558016

And per the shocks that's the same trouble i have been sorting out, just be sure not to ding them up so they are returnable.

If you have not already, after you remove the shocks and with wheels on the ground get a measurement on level ground from eye bolt to eye bolt, that's the static sag, then jack up the truck off the wheels and get that measurement that's fully extended dimension.
The formula is posted on my thread to find the remaining usable compression:
http://67-72chevytrucks.com/vboard/s...38#post6389138

I really don't know why the drive lines would be different unless they have a manual verses auto tranny or a different transfer case.. So the splines are just to tight to swap the slip yokes? I wonder if its just the diameter of the slip shaft or if its the splines? If its the diameter maybe you could just sand it down a little..

Re: 1971 K20- project just get driveable!!
 

Torque spec of the axle to spring U-bolts is 120 ft-lbs.

Re: 1971 K20- project just get driveable!!
 

I also found it to be a good idea to use a little oil on my U bolts the nuts didn't wanna rotate smoothly and squeaked without it. just remember lubricated threads actually will get a smidgen tighter than lubricated threads at the same torque setting..

Re: 1971 K20- project just get driveable!!
 

thx all for torque specs

axle drop from weighted to hanging is only ~2 in front and rear. so I am thinking ~3-4 inches of down shock travel and 5 to 6 upwards would be good. Is that what you are shooting for?


Here are the measurements I took on Monday which led me to state in previous post I have 3.75 of usable compression in the front:

Truck on lift, wheels off ground:
front- 19.75 bolt to bolt
rear- 21.25 bolt to bolt

Truck on ground, weight on axles:
front- 17.63
rear- 19.13

shocks extended:
front-22.75
rear- 26

shocks compressed:
front-13.88
rear-15.75

shock travel then ~9 in front and ~10 in rear.
axle drop from weighted to hanging is only ~2 in front and rear. so I am thinking ~4 inches of down shock travel and 5 to 6 upwards would be good. Is that what you are shooting for? I guess the design goal would be to have just enough downward to prevent shocks fully extending when axle bounces down and then all the rest would be for compressive travel. Golden question is just how much further (if any) can the axle go than the axle off ground (dangling) dimension?

axles from exact same trucks, just a year different. need to measure with caliper but will probably just swap whole driveshaft and be done.

Re: 1971 K20- project just get driveable!!
 

My book said 120 on the U bolts also, the other book said 150 but that book also covers 73 and later so i think they goofed and omitted the 70-72 truck.

In my research i figure that there is no need for the shock to extend but maybe about 1" past the fully extended measurement on the truck because the springs cannot physically move any further, so for example if you buy a shock that extends to 26" but your extended dimension on the truck is 21" then your going to find that the body of the shock is so long that you loose a lot of compression travel. the shorter the shock extended length the shorter the body, the more compression travel you will get.

I think 5-6 compression would be great for my truck but i have a 4" lift. I called a couple places today (yesterday) before i went to work, both of them said for my truck and a 4" lift that my 4.25" front and 4.5 rear should be ok.. I'm still a little skeptical but the only real way to know exactly how much compression your system has is to compress the springs till they bottom, but how? even if you picked up one wheel with a forklift the spring is designed to support the vehicle so that won't work.

>>Golden question is just how much further (if any) can the axle go than the axle off ground (dangling) dimension? <<

This is something i didn't consider, i just assumed the spring would hold its shape but I suppose its possible there could be some kind force that might make it flex outward?of change but i cant imagine it being that much. I would guess about 1" would be ok.

Re: 1971 K20- project just get driveable!!
 

leaf springs do pretty well with lateral location as long as the bushings are in good shape there will be some side to side motions just as an effect of the spring motion but it is mostly unnoticeable. crossover steering can make that feeling more apparent though

Re: 1971 K20- project just get driveable!!
 

I looked on Summit again tonight, and the next shorter set of skyjacker front shocks is for the stock setup, and are only 19" extended, which is about an inch short of what I need for my truck. Its a shame since the compressed length is only 12, which would give me a lot of compressive travel. It seems like they don't really have a shock for a kit anywhere between stock and 4 inches. Guess I will look at other brands or just hope the 3.75" of compressive is enough with the ones I have.

Re: 1971 K20- project just get driveable!!
 

Try looking at Bilstines, Allshocks.com or truckspring.com

I cant believe I'm gonna say this but if you go to the actual Fox shocks webpage they have a bunch of different sizes too, keep in mind my Fox shocks were specially valved for BDS and BDS only has "X" amount of sizes available with there valving for their kits. I considered going that route.

Re: 1971 K20- project just get driveable!!
 

Heres about the best I could find for fit:

http://www.summitracing.com/parts/ran-rs5001/overview/

13.25 compressed
21.125 extended

that allows 4.5 of compressive and over an inch below hanging position.

or these with about 4 of compr3ssive and a couple below hanging position:
http://www.summitracing.com/parts/tf...del/k20-pickup

http://www.summitracing.com/parts/tf...del/k20-pickup

How do the ranchos compare to tuff country to skyjackers?

Re: 1971 K20- project just get driveable!!
 

I cant tell you how they compare, the last set of shocks i took off my truck were 90's technology hydraulic shocks, all the new gas charged shocks seem to have longer body's.

I can tell you Bilstines are one of the better names out there.

Also Skyjacker seems to have a great rep in their lift kits for a smooth ride so ya might look there.

For me it would be a crap shoot from what you posted, I may lean toward the Skyjacker soft ride shocks if the measurements worked out, Overall I'd probably just shoot for the most travel you can get. Sorry i cant be more help

Re: 1971 K20- project just get driveable!!
 

I agree on all points. The bilsteins are pretty pricey for this work truck though.

It looks like I'm going to return the ones I have and go with the stock size skyjackers or tuff country. I did the math in a spreadsheet shown below. The 1000 lbs plow will pull the front down another inch and also I may see some sag over time with the new springs?

So the stock sizes will give me 5" or more and the tuff country will have 3" of extension and the skyjackers only about 1.5", and more with the plow on. I'm thinking the tuff country fit the best, hope they ride nice with the skyjacker springs. The bump stops are about 4.5" from the resting spot, so I want at least that much compressive travel.
http://i221.photobucket.com/albums/d...K20/shocks.jpg


Oh, and I put money down on this truck below. Previous owner is going to pull the nv4500 though before I can get it. Not sure when or which truck the 6bt will go into, but probably this ochre K20! more reason to have more compressive travel. I estimate the cummins will squat it by 0.5" more than the SBC. Spring rates are 550lbs/per inch and I believe that's per spring.
http://i221.photobucket.com/albums/d...173928_846.jpg

I hope its a D60 and not a D61 (he said it was pretty tall geared) but either way, the price was right.

Yanked apart the rear axle today and started on brake conversion
http://i221.photobucket.com/albums/d...0/P1010199.jpg

Stupid caliper plate diameter is too small by about 1/8" :( wont go over shoulder:
http://i221.photobucket.com/albums/d...0/P1010200.jpg

Re: 1971 K20- project just get driveable!!
 

Let us know how the new shocks work out.

What brand is that plate? Here's a couple more.
http://diy4x.com/cart/index.php?rout...&product_id=35
http://www.ruffstuffspecialties.com/...g/EHO5272.html

Is that your blue truck in the background? K20? C20?

Re: 1971 K20- project just get driveable!!
 

Yep, the blue truck in the background is my 1st K20. Its the project that this truck is distracting me from. Plan is to do nut and bolt frame off on that one. There is a build thread in my sig for that.

Plates are NW fabworks. I ground one out tonight with the die grinder. Took about 20 mins and now it fits good.

Also, working on spraying undercoating on the backsides of the bumpers, then I will paint the outsides semi gloss white.

I got the drums off and the bearing races out of the rear hubs. now its time to clean, paint, and put the new races in.

Re: 1971 K20- project just get driveable!!
 

Don't forget to pack the hub bearings with grease even tho its lubed by the gear oil. Thanks for the info on the brackets too!

Re: 1971 K20- project just get driveable!!
 

i was wondering what the factory assembly manual said about packing the bearings. i was planning on it but now that you mention it, dont see why it would be required. on the other hand, i dont think it would hurt anything either so why not.

Re: 1971 K20- project just get driveable!!
 

I don't know what the manual says but I was taught by my mentor to pack them. His theory was you are sure they are lubed until the gear oil works through them...

Re: 1971 K20- project just get driveable!!
 

Yes the manual does say to use a high melting point grease, chapter 4-20, this is the downloadable factory service manual i downloaded from here on the forum

I look at it like i would never rebuild an engine without lube nor any bearings, even on a manual tranny i would use some assy lube. Go look at where your fill plug is in relation to the hubs, its actually below the hub level, the hubs get gear lube by the lube being flung around and cornering ect. So how far down the road would you get before the bearings get properly lubricated? The grease will eventually dissolve into the gear lube.

Here's another thread for reference:
http://67-72chevytrucks.com/vboard/s...d.php?t=475710

Re: 1971 K20- project just get driveable!!
 

Just take a hard left and then a hard right;)

Thanks for the info from the manual. If not using grease, I'd still put assembly lube or gear lube on them. The question is whether to pack or just dip in lube. Still thinking I will just pakc since its not a big deal:chevy:

Re: 1971 K20- project just get driveable!!
 

Spent a lot of time this weekend getting the rear axle components cleaned up and painted.
Got the new rotors (still masked from painting) mounted on refreshened hubs. I achieved a workout hammering the new studs in!
http://i221.photobucket.com/albums/d...0/P1010227.jpg

Finished grinding the caliper mounting plates. Trying to figure out how to mount them so the caliper is in the best position.

Option 1: more protected from debris and getting hit.
http://i221.photobucket.com/albums/d...P101022411.jpg

http://i221.photobucket.com/albums/d...P101022414.jpg


Option 2: weird positioning but good angle for ebrake and bleeder.
http://i221.photobucket.com/albums/d...0/P1010226.jpg

http://i221.photobucket.com/albums/d...P101022413.jpg


Think option 1 makes more sense.

Oh, and bumper backsides undercoated. Figured paint would just get chipped off, I can always shoot more of this on when it wears down.
http://i221.photobucket.com/albums/d...0/P1010221.jpg

Re: 1971 K20- project just get driveable!!
 

A thread that may help?
http://67-72chevytrucks.com/vboard/s...9&postcount=15

I found this picture doing a Google search, forgive the non Chevy part.
http://moparforums.com/forums/93670-post19.html

Great progress!

Re: 1971 K20- project just get driveable!!
 

Being you are up in MN. I see you got a ton of snow in the last week or so.I guess she isnt plowing much snow yet.? I feel your pain... the 68 K1500 I was hoping to use to plow with isnt any where near ready, so I will continue to use the 86 CUCV M1008 i snagged a yr ago... she plows like a beast ..and burns oil! I always find that my ..."just get it working" plans always morph into much more... My first truck is still packed away in my garage Its a 68 K20 4 speed 292 truck.

Re: 1971 K20- project just get driveable!!
 

Whenever I rebuild a rear end or have the hubs off I always fill each hub with lube before installing the hub and fill the diff with lube, then jack one side of the truck way up and let the fluid fill the hub. Then I repete for the opposite side. I do this one more time with less angle after the first 2 to help make sure each hub should have the same amount in them. I used to pack the bearings but a lot of wheel bearing grease will gum up these newer type semi synthetic gear lubes and a lot of the stuff I work on require it.

Re: 1971 K20- project just get driveable!!
 

Seems to be the way things go! although i had to change the springs anyway with the heavy front plow and the eaton drums werent feasible to replace. we havent gotten hit too hard yet this year right where i am, probably 5 inches so far. north of here got dumped on!

thanks for the links. the dodge one is installed wrong, hes got the right caliper on the left side and the bleeder on the bottom. the other thread is a good one, but he has an extra set of holes in mounting plate. i suppose i could add some to mine.

after no luck finding parking brake lever brackets, i have a new set of calipes on the way from speedway with them included. I can then mock it up agqin this weekeend and see what angle works for the park brake and drill additional holes in the plate if necessary. i hope these calipers provide enough stopping power, thinking maybe i should have just played around with a set of big ones, like off a 2001 to 2004 2500hd. course that would involve custom mounting probably.

now i need to see about retuning the other caliper set to rock auto and the shcoks to summit:waah:

good to hear another method

Re: 1971 K20- project just get driveable!!
 

personally I dont mind rear drums... and if its a semi beater / plow rig to get running.. leave the Drums, and use em on one of the trucks u want to make mint.

Re: 1971 K20- project just get driveable!!
 

I think the biggest reason to get rid of the drums is due to the lack of parts available for theses rear axles.

Re: 1971 K20- project just get driveable!!
 

yep, the problem is there were at least two brake sizes in these. Mine is 71 only narrow (2 inch) config and drums couldn't be found. I was finding some listed for the wider (2.5 inch) 72 style.

Re: 1971 K20- project just get driveable!!
 

very interesting to me as I just purchased a califonia K 10 1972 with the same ochre color scheme and the parchment white interior. Mine is in a little better shape ! I plowed snow for 10 years (45 driveways) with a 1966 k10 . I miss that truck , it was a workhorse with a 292 cu inch 6. keep up the good work, looks like you are an experienced mechanic. I will be using my truck daily in my building business. I just can't let it sit !!

Re: 1971 K20- project just get driveable!!
 

So the good news is I got the new calipers from speedway's garage sale and the brackets look good for the parking brake. Bad news is these calipers are much smaller than the Eldorado or K20 fronts so they are of no use to me. I will take the brackets off and try and sell on ebay or something.

The brackets need to be trimmed a little to clear the mounting bolt. Also one caliper wasn't drilled for mounting these, so I drilled and tapped it.
http://i221.photobucket.com/albums/d...P1010225-1.jpg

With the new parking brake brackets on the caliper for a mock up:
http://i221.photobucket.com/albums/d...P1010222-1.jpg


I determined the best position for parking brake and bleeding is at the 3:00 position. That meant I had to drill and extra set of holes in the plate. Plate was hard steel or high grade steel so I had to go slow and was only able to make it with this nice cutting fluid. Love this stuff:
http://i221.photobucket.com/albums/d...0/P1010223.jpg

Got the bearings installed, and oil seals, and prelubed with semi synthetic gear lube.
http://i221.photobucket.com/albums/d...P1010226-1.jpg

Hubs are now on the truck, as are the dust shields and plates. Need to torque the nuts and install lock rings to preload the bearings. Looks like I should torque inner nuts to 55 ft lbs, back them off 1/4 turn, bend short tab on lock ring in, install outer nut and torque to 175, then bend long tab over outer nut.

Got the bumpers painted!
http://i221.photobucket.com/albums/d...P1010221-1.jpg

Re: 1971 K20- project just get driveable!!
 

Almost there. Might have it ready to go by the time I stop by for a visit. I need to get a good look at those rear disks.

Re: 1971 K20- project just get driveable!!
 

Nice work on those rear discs. The only reason I didn't go with discs on my truck is because I would have had to buy a very expensive caliper and big rotor to get the stopping power that the big drums on my D80 can provide. In your case, this is a great upgrade!

I also have become a fan of the Bilstein shocks. They aren't easy to fork the cash over for, but they ride and work so much better than the others I've had on these trucks. Makes Ranchos and Skyjacker shocks feel like a joke.

Re: 1971 K20- project just get driveable!!
 

I'm new,I've got a 70 k10,I wish I could find a truck like that to build,as far as axle shafts go,I Dana 44 and 10 bolt shafts will interchange and in some the stubs are different on non lockout trucks,as far as axles go ford ones will go right in there,as long as it's a 44,I know that for sure I mud with ford guys,yuck I know,but I enjoy tuggin them out

Re: 1971 K20- project just get driveable!!
 

That reminds me, when do you want to stop by? Drive the blazer! I've got 2 weeks off work starting this weekend, so this truck should really come together soon. Maybe you can help me get the rear bumper bolted on, its a pain with less than 3 guys.

Hmmm, I better price the Bilsteins out again, good to know there is a substantial difference. Not sure they have a good fit though for my lift, the one front one I looked at is as follows, which doesn't have much compressive travel left.

Bilstein 185590

no plow with plow
comp length 13.66 13.66
ext length 21.63 21.63
travel 7.97 7.97
comp travel 3.97 2.47
ext travel 4 5.5

I need to check to see if they have a shorter shock


good to know, should be easier to find an axle for the spare D44 given that!

Thanks for checking out my thread. Did you buy the one on ebay a month ago? I think the previous owner was on this forum too.

Re: 1971 K20- project just get driveable!!
 

I planned on coming after Christmas. I'm off til Jan 2nd after this weekend too. Those parts weren't for me so I kinda need to wait for the money to show before I buy anything that's not mine. Jimmy probably won't be making that trip. It's one thing to play in the snow for a little while at 30F. It's a completely different animal taking a 2+ hour drive at 10F without the top. Probably not in the C-10 either. Too much salt out there now. :(

Will just have to settle for the company car Fusion with the free gas and fold down rear seat for the long parts.;)

And I can help you out no problem. Bumpers get a little unwieldy don't they.

Re: 1971 K20- project just get driveable!!
 

Do you guys recommend a drop pitman for a 2.5 lift?

Also, anyone know of brake pads that are a tad thinner than others? Suppose I could sand them down. They are pretty snug on the rear rotors. Can turn by hand but there is drag there, probably 5 ft lbs or so

Re: 1971 K20- project just get driveable!!
 

I would see what the company that made the lift suggests. I've always used a drop pitman or raised steering arm on the diff. but the smallest lift I ever used was 4". Those pads will wear in pretty quick, they're supposed to drag a bit...

Re: 1971 K20- project just get driveable!!
 

I purchased the correction for mine but decided to see what it was like before i installed it. the block is still sitting on the shelf. i drives and handles just fine without it.

Re: 1971 K20- project just get driveable!!
 

Jud, on the rear pads, I'd almost just run them and let them break in. If you sand them and get them out of square it might cause a sticking or pulsating issue.

Re: 1971 K20- project just get driveable!!
 

I measured another set of pads that came preloaded on the stock front calipers and they are 0.020" thinner so I will just put them on and keep an eye on rotor temp. It sure would stink to warp them and have to replace, since they are behind the hub on these.

Ryan and Ryan, thanks for the input on the drop arm. OlBlueK20, I'm sure skyjacker would say run a drop arm but they have a drop arm they sell for the lift kit. Given that, they are inherently biased with advice to sell more parts.


Bah, throw some warm clothes on or a top on the blazer and rock it that way! Either way, sounds good on the bumper:chevy:

Re: 1971 K20- project just get driveable!!
 

Got the rear all buttoned up a few days ago, will upload pics soon! Just need to finish fabbing the new parking brake cable brackets and weld them on the eaton. Also, install a vent assembly in the eaton vent hole. and fill with semi synthetic.

I am replacing the rear park brake cables at the same time. Also got some Gr 5 carriage bolts to finish bolting the bed down.