AXN axle opt.
 

What years was this axle used? I'm looking for one to put in my 01

03- 07.5 (NBA) and 07.5-13 (NNBS) if I'm not mistaken. That's the 6 lug 9.5 14 bolt RPO.

Will an 09 axle bolt right in my 01?

The 09 yes would bolt in but the 07.5 up is a wider axle I believe.

Do you know how much wider. would that be total or just the spring pirches.

On mobile so hard to find but look up 1fastbricks thread on the 14bolts. Should have all the info you need and more

Edit: here you go https://www.performancetrucks.net/forums/gm-drivetrain-suspension-22/official-14-bolt-9-5-sf-truck-thread-467473/

Yeah it is on mobile I'll go to desk top. Thanks for that I had actually just remembered the stickies.

There's no info on the nbbs 14 bolts in the stickies that I could find. I've possibly found a couple but now not sure they will bolt in an 01 does anyone know the measurements of spring pads centre to center and backing plate to backing of the Nibs 14 bolt.

NNBS rear axle - FSC - Chevy Truck Forum
Found the info i needed here. looks like the NNBS bolts right into the NBS. I found a new 2013 GM OEM surplus 14 bolt with 6 lug axles at an auto wreckers up here for $850. complete. they say the rotors are rusty but i wont be using them anyway.