A-arms

[Zable49]

Ok folks, just curious.

3/4 ton 75-86 lower and upper a-arms are the same as 67-72 3/4 ton a-arms correct?

[hugger6933]

Don't think so. The 67-70 maybe had a different LCA. Hollender also list a different lower control arm for the 71 -72 model years. I know this from researching a 6 bolt disc brake upgrade using all stock parts. I also know that using the 68ish LCA [Iknow that year in particular because I have one of those with leftover parts]and the stock uppers a person can bolt in the ball joint for a 88-98 7200GVW 3/4ton and on the lowers press in the balljoints for the same truck and then your able to use that spindle and caliper. In effect giving you a factory type 6 lug disc brake front . Jim

[airdale94]

67-87 3/4 ton upper control arms interchange. The difference in the lowers is the disc brake spindle turn stop. The disc brake spindles take a different ball joint. But will install in either. Same for the uppers.

[Zable49]

Well I guess I should check to make sure I have that stop because the PO put discs on the truck few (10 ish) years ago from a newer truck and I dont know if he changed the arms or just spindle.

[Zable49]

Well since I guess the PO did change out the arms also since I have the "STOP" on them.. So knowing that I guess the whole front suspension is from the 84.

[68shortfleet]

Originally Posted by Zable49

Well since I guess the PO did change out the arms also since I have the "STOP" on them.. So knowing that I guess the whole front suspension is from the 84.

The drum brake and disc brake arms all have a steering stop on them. The location of the "stop" is different for disc. SO, you may not have 84 arms...

[Zable49]

Originally Posted by 68shortfleet

The drum brake and disc brake arms all have a steering stop on them. The location of the "stop" is different for disc. SO, you may not have 84 arms...

So the only way to find out would be to go find a set of 84's and do a side by side comparison...

[Tx Firefighter]

Your upper arms are definitely 73 and newer. You can tell by the slotted bolt holes on their front sides where the brake line bracket bolts to. These slotted holes were lacking in 72 and earlier arms.

My money says since you have later model uppers and later disc brakes, that the lowers are later too. It would only make sense.

[airdale94]

I can't remember the difference between the 2 lowers. You will either have to much turn and the tires will rub. Or not enough. The springs for the 73-87 are about 1" taller than the 67-72 drum. Both will fit and work. I used the 73-87 and after I was done chased a excessive camber issue on the left side. After some work I discovered I had a weak spring on the right. I thought maybe I mixed them up. Took it apart measured them, sure enough left side 1" taller. Did some other stuff came back measured them again, same length. Now what! Course I allready told you I "discovered" actually deduced I had a weak spring on the right. Anyway I ordered a new set (got the 68 drum) and installed them. Ah fineally! Camber perfect.

[67 cst swb]

those would have to be 3/4 ton arms... my memory is only 3/4 & 1 tons had the early style bushings like in the picture he provided

[Zable49]

Well to make things easier, I will just pickup ball joints and bushings for the '84 and if they dont fit correctly I will just return and order the older style.