TJ frame repair sections compatibility question

[grc340]

I am looking to purchase a rear control arm and centre section frame repair kit. Can anyone advise why some are only listed from 1997 - 2002? What changed on the frame from 2002? These are the ones i am looking to purchase for my 2003 TJ.

https://www.amazon.com/dp/B07NRGRDYN/?tag=wranglerorg-20
Thanks in advance
Gareth

 

[TheBoogieman]

Skid plate bolts. 97-02'-1/2"-13x1.5" grade 5. They switched for 03-06'- M12x1.75x40mm grade 8.8 or 10.9.

 

[grc340]

Skid plate bolts. 97-02'-1/2"-13x1.5" grade 5. They switched for 03-06'- M12x1.75x40mm grade 8.8 or 10.9.

Thanks for this. So I could just cut the captive nuts off and weld M12 on and they would work? What about the rear control arms, any small differences there?