72 K20 Front Axle U Bolts

[Brian 72 K20]

I just realized the second set I got doesn't fit. The first was from tuff country and said they'd fit-no. The second was from LMC, I assumed they'd fit since all they sell is truck stuff-no such luck. Maybe there's a bunch of different sizes of u bolts on these trucks. The big one measures about 7 1/4 x 3 1/2 and the small ones about 6 3/16 x 2 3/4 (or 13/16). Dorman measures the width inside across and the length to the inside of the bend. I'm looking at Dorman 929-839 and 929-715 which are pretty close and I'm hoping just my measuring error.

Can anyone confirm or know ones that will work?

[ohboy321]

Originally Posted by Brian 72 K20

I just realized the second set I got doesn't fit. The first was from tuff country and said they'd fit-no. The second was from LMC, I assumed they'd fit since all they sell is truck stuff-no such luck. Maybe there's a bunch of different sizes of u bolts on these trucks. The big one measures about 7 1/4 x 3 1/2 and the small ones about 6 3/16 x 2 3/4 (or 13/16). Dorman measures the width inside across and the length to the inside of the bend. I'm looking at Dorman 929-839 and 929-715 which are pretty close and I'm hoping just my measuring error.

Can anyone confirm or know ones that will work?

I recently ran into this same problem when trying to use Skyjacker UC2F U-bolts. One vendor had listed them as being used on 67-87 K10,K20 trucks and they have a 2-3/4" I.D.

I was installing a 1978 D44 and the tubes on that measure 2.870". The tubes on the 1970 D44 I removed measure 2.750".

What I ended up using was Tuff Country 17701 U-Bolts that have a 3.0" I.D.

[71Farming]

I went through the same headache trying to locate some ubolts for my 67 k20 with a closed knuckle front. Ended up using 2.75"x8" x5/8" (3) and 3.375" x 9" x 5/8" (1). I went longer length and cut to fit once final install was acceptable. Picked them up at a offroad shop in Auburn CA for around $47 out the door.

[Brian 72 K20]

Thanks, it's crazy both sets I got said they fit the K20 and no where close when going thru the top plate. I might order the ones from Dorman and if they don't work salvage the ones I have. The threads are a little dinged up but I'll try cleaning up.

[Brian 72 K20]

maybe I'm missing something. How'd you get the u boltsto thru the plates that sits on top of the spring if the id is narrower or wider? I would have to squeeze these tighter about 1/8 inch.

[70 gmc c2500]

To the OP, you need to first identify your front axle and then make sure your top plates match the axle diameter then go from there. Give RuffStuff Specialties a call and he'll get you right. https://www.ruffstuffspecialties.com...BoCjscQAvD_BwE