Relocating center bolt hole in leaf springs?

[Mustard72]

I've searched but couldn't find an answer to this question. I'm going to be replacing the leaf springs on my 72 C20 (actually a 69-70 GMC frame, for what it's worth), as the ones on the frame are garbage, mismatched, etc. The only new leaf springs I can find with the 24" length from the front eye to the center bolt are a little lighter than what I want for towing the horse trailer around, but there are plenty of same overall length leaf springs out there with 26" front eye to center bolt lengths. I'm thinking about simply drilling a new hole for the center bolt through the leaf pack 2" towards the front of the existing hole on a set of these springs to regain the 24" front dimension and thus not change my wheel base or require moving the spring mounting brackets around. Has anybody else done this? We don't have a spring shop anywhere near here that could custom make a set of springs, and if this trick works, the springs I have in my sight are rather affordable (although shipping is expensive, obviously). Otherwise, I could add a leaf or two to the lighter ones that already have the 24" front length, but that would require pulling the center bolt, possibly replacing it, and possibly replacing spring u-bolts, etc. I'm thinking if I could just drill an additional hole, it would be much more straight forward.

[Hertzdaddy]

Personally I think I would first try every option other than drilling the spring. While I've never drilled leafs I have cut through some springs. Spring steel is tough stuff and will eat up some tools. Also, I don't know for sure that it would weaken a leaf spring to have an extra hole in it, but it would bother me to have it there.

[bdiamond]

You can redrill the centering hole on the spring perch. I've never heard of a 24" spring. How are you measuring?

[cdowns]

i'd worry about detempering and causing a wek spot in the spring

[cdowns]

Originally Posted by bdiamond

You can redrill the centering hole on the spring perch. I've never heard of a 24" spring. How are you measuring?

read his post he is not lookin for a 24" spring and he explains quite well how he is measuring

[Mustard72]

It's 24" from the front eye to the center bolt. Doesn't sound like redrilling a center hole is a good idea (figured as much, but thought I'd ask). I don't believe there is enough room on the spring perch to drill a new hole 2" forward, either How about a new hole on the axle mount that is welded to the axle tube?
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[oldman3]

Why not make up a 1" thick block, drill one hole for the rear axle and another hole 2" forward for the spring. This should have everything lined up the way you want and the U-bolts will hold everything in place...Jim

[Mustard72]

That should work, too, shouldn't it.
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[bdiamond]

Originally Posted by cdowns

read his post he is not lookin for a 24" spring and he explains quite well how he is measuring

He was referring to a 24" front half. I got that... Every truck I've seen has had a 26" front half.

[bdiamond]

http://www.truckspring.com/products/...)__22-409.aspx. I stand corrected.... The older narrow ones.

[Mustard72]

That's pretty much the only one I could find with the 24" front half dimension, but it's a little light for pulling 7,000 lbs of gooseneck horse trailer with, I think. The 419 version is heavier (not to mention considerably less costly) but has the 26" front half dimension. I'm thinking of getting a set and making them work; either by drilling extra mount holes on the spring pads welded to the axle tubes or by making adapter blocks like Jim suggested, although that might raise rear ride height a bit.
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[Bigdav160]

Did the factory change spring mounting locations? They seem to offer different centers on springs.

[bdiamond]

Might be simpler to just swap to the wider spring hangers and go with the later model 52" or maybe even 56". I think the duallys and all heavy applications had 56". I see your 24" spring is still 52" overall. I didn't realize they shifted the center pin on any.

[Mustard72]

Originally Posted by Bigdav160

Did the factory change spring mounting locations? They seem to offer different centers on springs.

There is an additional page that goes with that chart that designates which spring goes with which truck. It covers many different models, not just 127" wb pickups. Good info, though. IIRC, only two of the springs apply to 2wd C20's, and they both have the 24" front dimension. 3941631 and 3941642
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[Mustard72]

Originally Posted by bdiamond

Might be simpler to just swap to the wider spring hangers and go with the later model 52" or maybe even 56". I think the duallys and all heavy applications had 56". I see your 24" spring is still 52" overall. I didn't realize they shifted the center pin on any.

I'll look at that. One issue might be that the frame is dimpled out to position the existing hangers.
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