67-87 1/2 ton spindles on a 70

[GMC70c20]

I was doing a little reading and someone said you can use a 73-87 spindes hubs and brake asembly on a 67-72 control arm (assuming they were bolth 2 wheel drive) series truck. Is this so? if it is how easy of a swap is it?

[jimmydean]

67-70 and 71-72's use different lower ball joints. I think the 73+ uses a different ball joint too. But as I understand it, you can press a 73+ ball joint into a 67-72 control arm and use the 73+ spindle. You will need to change the tierod ends, but there is a kit that adapts the larger tierod end to the smaller tierod.

The easiest thing to do is to pull the whole cross member and steering from a 73+ and bolt it in. There are plenty of threads about this conversion. I try to stay with as many "same year" parts as possible to make it a little easier when I need to replace something.

[GMC70c20]

I could probably make tie rod adapters and do any machine work needed (if any) on the spindles, I took a 2 year collage cnc machining program at a local collage. Are the ball joint normally pressed in? I thought that they bolted in.

[chopper103in]

Originally Posted by GMC70c20

I could probably make tie rod adapters and do any machine work needed (if any) on the spindles, I took a 2 year collage cnc machining program at a local collage. Are the ball joint normally pressed in? I thought that they bolted in.

upper ball joints bolt in
lower ball joints press in

[crazy longhorn]

If your crossmember is in good shape, the easiest route to your swap (IMO), is to just replace the upper & lower ball joints(use for the yr of the spindle), & replace ALL the steer linkage (inners,outers,adj sleeves, & the centerlink, with pitman & idler). The pcs can be used from a 73 up donor truck, then just add your new balljoints/tierod ends. Dont forget to check the old steel a arm bushings, they hold up pretty well if they have beem greased in their past life, but you may find some wear. As far as balljoints & tierod ends/sleeves(just as a note), the 71-72s are different than the 67-70. 73-up also made a change .......they use the same lower balljoint , but the upper balljoints, & the outer tierod ends are different. If your a arm bushings are all worn out, it probably will be CHEAPER in the longrun to swap the complete crossmember assy as mentioned in an earlier post......i dont think easier tho best of luck, L

[GMC70c20]

well I found a 81 1/2 ton 2wd for $50, The trucks still intact but the engine and trans has ben pulled. Let me get this straight if Where to use my 1970 conrol arms I would still use 81 ball joints and inner tie rod ends, and use 1970 stuff in the rest of the suspension?

[lolife99]

If that's the route you want to go,... Use your 1970 control arms. Buy: 1981 everything else. This includes upper and lower balljoints, inner and outer tie rods, idler arm, center link and steering arm. If the '81 is a power steering truck, use the box as well. This will ALLOW the use of '73-87 spindles and brakes. Also the '81 has rubber bushed a-arms,...which some people think is a plus. Use them too! Now you need to use the mastercylinder and proportioning valve also from the '81. All of this work depends on if you are rebuilding as you go,... or just swapping.

[GMC70c20]

I was gonna get all new bushings, ball joints and inner outer tie rods and idler arms. Is the reason whay I would have to use 81 stering stuff is just because the tie rods are different? I could make and apdpter pretty easily on a lathe.

[lolife99]

Are you converting from a 3/4 ton to 1/2 ton?

[GMC70c20]

yes

[lolife99]

I think the hole in the lower control arm is BIGGER on the 3/4 ton models. This will require you to use the 1/2 ton lower control arms. For making everything simple,... I would swap everything from your donor truck. Either with the crossmember,... or without.