Re: 1972 Blazer CST Frame off Project in NC
 

Looking good!

Re: 1972 Blazer CST Frame off Project in NC
 

So, I need some opinions. I am reassembling various frame components now that I have the axles hung. Today I noticed something that I never have before. In the first pic, I have this bracket that is bolted to the frame on the drivers side - no idea what its for - but I swear it looks like its to keep the leaf from going too far back. There is probably 1/4" between the bracket and the leaf eye.

In the other pics (of the passenger side), no such bracket, but there are holes in the frame for one to bolt in.

So, 1) whats the bracket for, 2) is it okay that there is that little clearance between it and the eye, and 3) should there be one on the passenger side?

Thanks!

Re: 1972 Blazer CST Frame off Project in NC
 

You are right on! This bracket is to limit the travel of the leaf spring on only the Drivers side of the truck. Also on the front spring support you should also have a strap that is spot welded onto the front spring perch. Both these items are factory stock to help keep the truck under control if the spring fails!!! Obviously they (GM) had failures and this was the quick fox for it.
There should be a little more clearance. If you put lifted springs on your rig. This might have reduced the clearance.

Your build is looking great!!

Re: 1972 Blazer CST Frame off Project in NC
 

Thanks 72 Jimmy!!

I do have a 'steel plate' welded in the front side of the drivers side hanger - I assume thats the strap you mean?

Glad to know I don't have to try to source another vintage part!

So, any ideas on how much clearance I need for that bracket? Looks like i need to break out the sawzall!

Re: 1972 Blazer CST Frame off Project in NC
 

Yeah the stop won't fit with the new springs and shackles. I have the exact same issue as you. I have a set of ORD customs with approximately 2" lift over stock and using their shackles. I'm debating whether I will bother bolting it back on or not.
I think you would want more space than what is shown in the picture. I think that is going to be banging everytime you get some spring compression in the front.

Re: 1972 Blazer CST Frame off Project in NC
 

Thanks Jeff - - thats almost exactly my setup. ORD customs with about 3" over stock. I think I'll email Chris and Stephen at ORD and get their opinions.

Re: 1972 Blazer CST Frame off Project in NC
 

I planned to elongat the holes on the bracket to give mine more clearance. It would be nice to know how much clearance really needed.

Re: 1972 Blazer CST Frame off Project in NC
 

I found these instructions for the Service kit installation of this in a for sale thread on this site. These were for Dealer service campaign. If you read it says under full vehicle weight the stop should be tightened with 1/8" of space to the spring. This is with factory spring geometry but it seems too close to me. I would think you would get hard contact and banging under fast spring compression at least looking at the spring geometry of the ORD / Alcan custom springs. They are designed with that thinner gauge higher leaf count so they do deflect a lot more than factory set up.

Anyways food for thought ...

Re: 1972 Blazer CST Frame off Project in NC
 

Thanks Jeff, that is an awesome find!

I did exchange emails with Chris, the engineer at ORD. His recommendation was to trim them back (at minimum) or to remove them (at maximum). He did not suggest a clearance amount, so the dealer campaign docs you found are perfect.

I also agree with your observation of the softer springs with greater deflection from ORD/Alcans too though - so i think its gonna be more clearance than that in the end. That said, I have been thinking about his suggestion to remove them too. The obvious idea of the bracket is to provide some modicum of steering ability in the event of catastrophic spring failure. But when you see the difference between the stock shackles and the beefy ORD shackles - its really hard to imagine how they might fail, or if they do, steering may be the least of your worries....... :)

I'll mull it over for awhile...

Re: 1972 Blazer CST Frame off Project in NC
 

Ok, been pretty busy the last 3 weeks, but have made some progress. I do feel like its been 1 step forward, 3 steps back though...... I've started lots of things and not really finished anything. So heres whats been going on:

1) Mounted shocks, bump stops and a custom uhaul receiver hitch - complete.

2) Ran all brake lines - front complete, not the rear. I ran into an issue....realized the axle builder put the brake backer plates on the wrong sides, so a spent a Friday night cracking into the axle, draining it and pulling the axle shafts so that I could swap the backer plates.....not happy. I hate redoing work that I thought was done.

3) Ran all fuel lines. Not complete. What a crazy assortment of lines I got from Inline Tube.....thanks to many Member's posts, I was able to sort out enough to get it done.....right up until I figured out 2 things. In NC, I don't need emissions inspections, so I am not going to use the charcoal canister and lines AND I was sent the Pickup main fuel supply line, not the Blazer.......UGH. Not hard to redo, just more lost time.

4) Fuel Tank. Decided to carve into my original tank and get the fuel filler pipe off and have it transplanted onto the reproduction tank. Took awhile to find a radiator shop willing to do it, but its at one now and hope to get it back this week. Meanwhile, the original straps are soaking in evaporust (that stuff is crazy good) and will get repainted today.

5) Steering gear box mounted. Complete. Like my new Redhead gear box a lot. Great folks there too. Took time with me on the phone.

6) Front brakes - complete, mostly. Got the new Wilwood D-52 calipers on and all the hoses connected. My old school 15" Rally Wheels wouldn't clear - even with the .25" wheel spacer that others have used. Tried different wheels, all had issues. I will be going with an aftermarket wheel, the Mickey Thompson Classic III - in a 16". After ordering a 15" with 3.6" backspacing, it cleared the caliper itself great, but only cleared the caliper mounting bracket by 1.45MM. Too close for comfort for me.

7) Rear Brakes - UGH. I decided to do those last Friday, which is when I discovered the backer plate issue. So, I restarted yesterday. That's when I realized I am an idiot......I was starting by installing the parking brake cables (Inline Tube - GREAT quality) only to realize that if I weren't an idiot, I would have ordered them 3" longer than stock to accommodate for my 3" of lift. Oh well, nothing time and money wont fix!

8)Engine and Trans Crossmembers - Complete!

9) Center Link - Tried to tackle that yesterday as well and was able to get the Right end of rather easily, no such luck on the left end. I tried penetrating oil, BFH, BFW, Torch. Nada. Gonna attack it again today, and if no dice, will take it to a shop this week.

I guess the advice I need now is this - which is cheaper a psychiatrist or an alcohol addiction! :)

Re: 1972 Blazer CST Frame off Project in NC
 

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Re: 1972 Blazer CST Frame off Project in NC
 

My '71 K5 had those too.....the way it looked to me was that the factory springs, being negative arch (upward)...the shackle would move forward under compression rather than moving backward like a positive arch would.

I would think that using those with lift springs would severely limit the spring travel as the shackle tried to move back under compression and contacted the bracket.

Re: 1972 Blazer CST Frame off Project in NC
 

I may have a small problem - - Does anyone know a source (or an alternative) for the fuel tank stand pipe? Not the Filler neck, but the ventilation pipe thats further to the rear. It seems a 'helper' at the body shop may have thrown it away accidentally. The search is still on, but I am NOT hopeful.

Appreciate any help!

Re: 1972 Blazer CST Frame off Project in NC
 

nice build, let me look, not using mine. vent is hooked different than stock, since ours doesn't have a rollover stop

Re: 1972 Blazer CST Frame off Project in NC
 

Thanks Jim - - So, how did you hook yours up rather than use the stand pipe? I am open to better ideas than reusing a stock part just because its stock....

Re: 1972 Blazer CST Frame off Project in NC
 

Shouldn't be too tough to scare up. I'll have a spare but can't part with one until my blue blazer is in paint. Try a wtb post on blazer parts board in the meanwhile.

Re: 1972 Blazer CST Frame off Project in NC
 

Could you please share the Bilstein part numbers you used for both Front and Rear shocks?

Re: 1972 Blazer CST Frame off Project in NC
 

Where did you get your brake lines from??

I went with different bilsteins. I used the ORD springs also. So far so good. We are at similar build times right now. My rear diff will go in this weekend. I went with the 14 bolt.

http://img.photobucket.com/albums/v6...psfw9a2mxw.jpg
http://img.photobucket.com/albums/v6...psictxo81e.jpg

Re: 1972 Blazer CST Frame off Project in NC
 

still thinking, that build ought to be in the smithonian

Re: 1972 Blazer CST Frame off Project in NC
 

No problem. These are the Bilstein 5125s, which are universal. I went with an 11" in the rear and an 8.60" front, which was to adjust for my 3" lift. The specific items #s are 33-185606 Front and 33-104652 Rear. Chris at ORD helped me select the right length.

You may notice I mounted them with the rubber boots down. You can mount them either way, but my OCD kicked in and if you mount the rubber boots up, the word 'Bilstein" is the upside down.........Sad, I know. :)

Re: 1972 Blazer CST Frame off Project in NC
 

Inline Tube......went with stainless steel. Very pleased with the quality of their stuff. Dan there has been really helpful. While there are NO INSTRUCTIONS with their stuff, the brake lines were the easiest ones to figure out. My pics can help you - - and 72K5CSTDarkOlive's sure helped me.

My flexible lines came from ORD.The only issue there is the rear flex line comes with 3/8s female and the Inline hard lines are 7/16s at the rear diff. 2 Dorman adapters for $10 fixed that.

Your shocks are SICK. We are building different rides, but yours looks awesome so far. Good luck!

Re: 1972 Blazer CST Frame off Project in NC
 

I think I may have sourced one, but still curious!

Re: 1972 Blazer CST Frame off Project in NC
 

Maybe I can spend some time on it tomorrow, booked today. I think it was from a motorcycle