Body Bushing Bolt P/Ns for MOST G-body applications (YMMV)

[69hurstolds]

I see the following posted around different places...and, well, it's partially incorrect. It won't matter if you find the GM part number bolts, as they'll be correct for the application, but if you use store boughts, you may be surprised. I have highlighted the incorrect stuff in red.

Position 1 uses GM P/N 10049638 (sold ea., 2 needed). Bolt is 12 X 1.75 X 95mm long.
95mm is not common so you have to use 100mm.

Position 3 uses GM P/N 14085301 (sold by pkgs. of 5, 2 needed). Bolt is 10 X 1.5 X 55mm long. Also need two nuts.

Position 2, 4, 6, 7 uses GM P/N 3524497 (sold by pkgs. of 5, 8 needed). Bolts are 10 X 1.5 X 80mm long.

Position 1, p/n 10154656 or 11508134 were replaced by 10049638, actually is an M10 x 1.5 x 95 mm bolt. Also, it requires push nut retainers for them, p/n 4495047 superseded by p/n 11501849, M10 x 1.5, 24mm diameter push nuts.

Aftermarket bolt:

(5) M10-1.50 x 95mm Hex Head Flange Bolt Non Serrated Class 10.9 Zinc DIN 6921

(5) M10-1.50 x 95mm Hex Head Flange Bolt Non Serrated Class 10.9 Zinc DIN 6921

www.clipsandfasteners.com

Position 3 aftermarket bolt:

https://www.fastenal.com/product/details/11115632

Or- [pack of 10]

(10) M10-1.50 x 55mm Hex Head Flange Bolt Non Serrated Class 10.9 Zinc DIN 6921

(10) M10-1.50 x 55mm Hex Head Flange Bolt Non Serrated Class 10.9 Zinc DIN 6921

www.clipsandfasteners.com

The 14085302, replaced by 22504401, replaced by 3524497 bolt for positions 2, 4, 6, and 7 is M10 x 1.5 x 85 mm. No big deal, but this is what's in the GM parts information.

Aftermarket bolt:

(1) M10-1.50 x 85mm Hex Head Flange Bolt Non Serrated Class 10.9 Zinc DIN 6921

(1) M10-1.50 x 85mm Hex Head Flange Bolt Non Serrated Class 10.9 Zinc DIN 6921

www.clipsandfasteners.com

Factory bolts are usually tapered on the end, most aftermarkets are not. Still should work.

 

[john87442]

Like usual you’re on point and a wealth of knowledge.

 

[69hurstolds]

The proof is in the pudding, however. Are these GM replacement bolts the PROPER length as the factory bolts? Honestly, I never measured any orginal bolts. Anyone have some used ones that can measure?

Many of the original bolts, IIRC, were tri-lobular style bolts, which have a tendency to resist friction buildup during install and vibrational loosening after torquing.

 

[john87442]

Yeah I currently have some on the bench that I removed from my 87 442, when I get home tonight I’ll measure and snap a picture.

 

[78Regal350]

Here are some pictures of my original bolts, as well as a picture of the new replacements I ordered from belmetric.com (which were VERY affordable). The 1st pic is of a #2, 4, 6, or 7 bolt which has about 75mm of thread. The next is the #3 bolt, which is a bit over 50mm of thread. The 3rd picture is a core support bolt, which is 95mm.

 

[Hurricane77]

One does have to be careful with the body mount stuff, especially if there's been any repair done.

For example, this rear body mount repair kit:

78-88 Rear Body Mount Bolt Pocket Kit | Dixie Restoration Depot

www.dixierestorationdepot.com

The bolt and cage nuts included are not the same as factory. I haven't measure them, but factory bolts do not thread into them. They may be imperial instead of metric.

These cage nuts however, do match the factory bolts

78-88 Captive Body Mount Nut | Dixie Restoration Depot

www.dixierestorationdepot.com

I haven't yet installed the repair kit, But I'm likely to replace the cage nuts with the proper ones.

 

[69hurstolds]

Interesting. It actually appears around 80 mm for the 2, 4, 6, and 7 bolts. So while 85 mm may indeed be ok, aftermarkets with 75-80mm length without the taper point seems more logical. And maybe more affordable?

Strange too, as I recall my 84 had tri-lobe bolts in them when removed. And they were originals. AFAIK, GM never had over the counter replacement tri-lobes, they were all the general round bolts.

 

[78Regal350]

When I bought all new bolts from Belmetric last spring, it cost me $34.57 (including tax & shipping) for (10) 80mm bolts, (2) 55mm bolts, and (2) 100mm bolts with nuts.

 

[RabbitHoleSS]

Post in thread 'Body bolt sizes 78 monte' https://gbodyforum.com/threads/body-bolt-sizes-78-monte.58495/post-494457
I saved this years ago, all the bolts fit.

 

[69hurstolds]

Post in thread 'Body bolt sizes 78 monte' https://gbodyforum.com/threads/body-bolt-sizes-78-monte.58495/post-494457
I saved this years ago, all the bolts fit.

Bonus. Thanks. I did note, however, the list provided by ssn696 needs a bit of tweaking as well. For example, the 642 bolts are actually the 60 mm size, and the 648 bolts are the 80 mm length. He got them backwards. They come in packs, so if you buy the whole list that way, it shouldn't matter, but be careful if buying individually at the store or if only needing to buy one pack.

Based on his list, you can have it all from McMaster Carr with stuff left over for around 75 bucks in today's prices. Like a dumazz, I already bought all GM junk, especially the radiator support assemblies. It seems like those have about 60 pieces per side with the bushings and stuff. And from GM, that can nickel and dime you to death.


Bolt listings from McMaster Carr (field verified to fit and work):

Sack O' Nuts (pack of 50):

Oversized washer (shimming):

Washer, Zinc Flake (Position 1 and shimming):