Where can I get e to get the proper J-nut or best substitute for the bottom fender I believe it's 3/8 GM 387730

 

I actually just bought them for my car..you can get from inline tube or on ebay you can get the whole front end set or just the bottom bolts with speed nut clip on the inside. I believe whoever is selling them gets them from in-line tube.

 

Motor city fasteners. They have all.

 

GM standard parts lists them as a J-nut with 3/8-16 threaded nut.

Clips and Fasteners has them in a box of 25. May be a bit much in quantity, though. 3/8-16 with a panel thickness of 0.050" to 0.090". Not sure about the reach.

Their p/n is A5170

J Type Cage Nut 3/8-16 Screw Size (clipsandfasteners.com)

 

pretty sure motor city sells inline tube bolt set..
Either way they are easily available

 

_trkparms=amclksrc%3DITM%26aid%3D111001%26algo%3DR EC.SEED%26ao%3D1%26asc%3D20160908105057%26meid%3D5 6a7c4bba3a144748692c1493543e2a8%26pid%3D100675%26r k%3D3%26rkt%3D15%26sd%3D312334448508%26itm%3D16341 2757799%26pmt%3D1%26noa%3D1%26pg%3D2380057%26brand %3DInline+Tube&_trksid=p2380057.c100675.m4236&_trk parms=pageci%3Acf7ebc0b-c73b-11ec-b5d8-e23263c1f8e0%7Cparentrq%3A721e35001800a0ac23b7e318 fffcc470%7Ciid%3A11
I used this kit from Inline Tube. It had almost everything I needed including hardware for inner and outer fenders, radiator support, headlight buckets and grills. Only thing it didn’t have for the front clip was door hinge and hood hinge bolts. I used almost everything in the kit except a few clips. Everything has the factory correct markings too.

 

My experience with inline, most of their stuff is incorrect. If you see them at an eventbselling At their booth, if yiu can get their attention, they didn’t bring any. Lol.
you can get a box of the j nuts, and a box of the bolts. Done. Motor city only sells by the box.

 

https://www.amkproducts.com/

 

try these joints
https://www.oemhardware.ca/catalog_auto.htm
https://www.loc8nearme.com/new-york/...upply/3064988/