1971 K10 U-bolt Issues (Rusty, Not So Trusty)
 

I have my '71 Chevy K10 completely apart. I decided it would be a good time to put a small 2.5" lift on it. When I got to the rear passenger side, the bracket that holds the U-bolts, or the rear anchor spring plate (whatever it's called) broke. I can't find anything online to help me find the right size.

I measured them and got 3.250" from peak to peak and 4" from center of one hole to the center of the other like the attached picture. I'm told that's the wrong size. My rear end is a 12 bolt rear end, and I'd think based on how terrible the rust is/was that it's all original.

I can't do anything else with the lift until I can replace that. Any help would be extremely appreciated!

Also, I searched the whole site and asked questions in a Facebook group and got more confused. I was told that the 12 bolt only has a 3", not the 3.250" I measured. However, the plate fit snug on the axle.

Any other questions or anything I missed, please just ask and I will answer to the best of my (limited) knowledge.

Re: 1971 K10 U-bolt Issues (Rusty, Not So Trusty)
 

You are looking for orig. GM pt. # 3824491. Later changed to 3762845 and 3996593. Applications include 1969-72 Blazer, 1971-72 K10/K20 exc. HD rear springs.

https://67-72chevytrucks.com/vboard/...1&d=1436200256


Per 5/81 Parts book:


GR. 7.518 PLATE, REAR SPRING U BOLT ANCHOR
QTY 2 3762845

65-66 K10-Kg10
69-71 K10-K910-K15
71 K20-K25 W/STD
SPRINGS .... /SUP 3824491

Re: 1971 K10 U-bolt Issues (Rusty, Not So Trusty)
 

Yes! That's exactly it. I took the broken one off and remeasured. It is definitely only 3" and not the 3.250" I thought. I looked up the parts numbers you offered and it says they are for 73-87 Square Body trucks with 3.5" axles. They look quite similar, but I'm just worried about the size they're made for. Either way, thank you for the response!

Re: 1971 K10 U-bolt Issues (Rusty, Not So Trusty)
 

if you can't find them p.m. me, i've got a few of them laying around my parts stash.

Re: 1971 K10 U-bolt Issues (Rusty, Not So Trusty)
 

square body U bolts were mounted with the plate on top of the spring pack not under the axle like your picture