Rear Shock Question?

[YourBuddy'sTruck]

I'm about to change the rear shocks in my '70 C20.
I've never done this job before, but after reading about it here, I feel I can easily nick this one myself.
Crawled under to shoot some PB on the bolts and noticed that I have 2 Pin Locations for Shock Mounting?
I'm clueless as to why there would be 2?
One is 16 1/8" from the bottom mount.
The other is 18 1/4" from the bottom mount.

Any ideas as to why there are two?
Would one work better than the other?
Did someone do this just to raise the rear end two inches?

I do haul heavey pallets of products once a week.
Thanks for any advice and/or explanation.

[Blazerowner]

I don't think I've seen that before but seems like if you mounted it to the top the bottom stud would hit the shock. Maybe someone had a dual shock setup or something at one time. I would just use the same spot since it's already worked this long.

[YourBuddy'sTruck]

I hear you.
I do reserve the right to cut one off if needed, but you're making good sense to me.
I may get to it later today, but then again...the weather is too nice to lay under the truck.
Think I'll throw empty beer cans in the back of it instead.
Have a great Memorial Day Weekend!
Cheers!

[JointTech]

the top one is the correct one. I suspect its either stripped or it spins and you cant tighten the nut so he drilled a new hole for a new shock mount.

Mine was jacked as well but I cut it off, drilled out the hole and pout the replacement shock mount back in the same hole.

[YourBuddy'sTruck]

Just a follow up...
I used the lower pins, or rather replaced the lower pins.
The "originals" were actually loose and I think it was PO that did that.
The ones in use were also loose.
My new ones are not loose.
It is impossible to work a ratchet inside the frame itself, but I was able to file the new pins to accept a 15/16" open end wrench.
That let me get the last bit on them to tighten up and will also aid in removal years from now.
All in all, the job went as well as it could and I believe my ride is improved, but will know more when I actually haul a load in the bed and bounce my way on and off the Miller Ferry Boat.

BTW...$47 Monroes and $7-8 Mounts.

[YourBuddy'sTruck]

yep...I'm an idiot.
See Photo?
Two man opperation or mount solo, then come back with an extension?
There is a hole in my frame where I can get the socket in place...Then get outside the frame inside the wheel well?
Insert an extension and I could totally get a great bite on the Shock Mount!
Anyone else know what I have here?

[YourBuddy'sTruck]

I spent two days thunkin'bout this job!?