A31 on fender tag what does it mean

[jlemler]

I have a 1970 Cuda with a 383.  The fender tag has A31 on it.  This means it has a hemi suspension.  What exactly is included in a hemi suspension? Also am I correct with sway bars.  When I say mine has a front sway bar and no rear; however, if it was built after a certain date would it have a rear sway bar?

Jeff

[GY3R/T]

A31 is an Axle Package.  8 3/4" , 3.91 sure grip. Torque drive fan , Max cooling , Hemi suspension.
    Rear swaybar is an option. S41

[1 Wild R/T]

A31 can have a couple of meanings, it depends on when it's located.....     If it's located when 825 is on the attached tag then it's the scheduled production date... If it's in the next row up it's an axle code...

Oh if it's in the 825 location it's a Oct 31st SPD

[Cuda Cody]

   It's either the axle package (if it's on the 3rd line up from the bottom) or if it's on the 2nd line up from the bottom.  @jlemler

https://decoder.e-bodies.org/1970-mopar-fender-tag-decoder/

[6bblgt]

on a '70 'cuda & coded on a broadcast sheet:

S13 = "Heavy-Duty" HD suspension STANDARD 383 & 340 'cuda (BS)
S15 = "eXtra Heavy-Duty" XHD suspension STANDARD 440HP, 440+6 & HEMI 'cuda (BS)

the S13 HD suspension included a rear sway bar after the production of AAR & T/A cars (cars built May, June, July)
the S15 XHD suspension is OPTIONAL on 383/340 'cuda & included w/OPTIONAL axle packages A31 (3.91s) & A36 (3.55s)

S15 XHD suspension included: bigger torsion bars, bigger leaf springs & bigger shocks

[jlemler]

"S15 XHD suspension included: bigger torsion bars, bigger leaf springs & bigger shocks"

OK, how big are the torsion bars, leaf springs and shocks?  The A31 is for the axle package.

[Cuda Cody]

Your torsion bars will have numbers on the end telling you what size they are.


781   #1857781 Left Torsion Bar 41" x .92" (STD 426 Hemi & 440) & optional S15
780   #1857780 Right Torsion Bar 41" x .92" (STD 426 Hemi & 440) & optional S15

"S15 XHD suspension included: bigger torsion bars, bigger leaf springs & bigger shocks"

OK, how big are the torsion bars, leaf springs and shocks?  The A31 is for the axle package.

[anlauto]

0.92" torsion bars, springs will just have more leafs and a short half leaf, shocks look the same on the outside.

[6bblgt]

I think this is accurate for 1970

torsion bars:
S13 = # RH 1857 778 & LH 1857 779 * .90" diameter
S15 = # RH 1857 780 & LH 1857 781 * .92" diameter

leaf springs:
S13 hardtop = # 3400 043 * 5 leafs
S13 convertible = # 3400 044 * 5 leafs
S13 Trans Am = # 3400 048 * 5 leafs
S15 = # RH 3400 024 * 6 leafs & LH 3400 034 * 5-1/2 leafs