Hump fastener/hardware size? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**General23cmp** · 08-06-2016, 08:39 PM

What size are the bolts, including length? Do they have flat washers on both sides? Lock washer? Maybe they're sheet metal screws?

davepl · 08-06-2016, 09:12 PM

Captured nuts, if I recall, probably 5/16x3/4 bolts as a best guess.

**General23cmp** · 08-06-2016, 09:27 PM

That really makes sense. Didn't consider the difficulty of fastening with loose hw.

**General23cmp** · 08-07-2016, 01:01 AM

Can anyone confirm the size? Also, the captive nuts, are they just square nuts welded in, or are the "fancier kind" with a cage around them?

**Blue/72** · 08-07-2016, 01:29 AM

I have a set I will check size tomorrow

**CUSTOM/10** · 08-07-2016, 06:52 AM

I just did mine yesterday, 10 - 5/16-18 thread x 3/4" washer head bolts. This is what's on the original installation with the nuts welded under the floor. The capture nuts should work good if your adding a high hump.

Gary

**General23cmp** · 08-07-2016, 11:01 AM

The nuts welded to the floor...simple square nuts tacked or some sort of caged nut?

**CUSTOM/10** · 08-07-2016, 11:45 AM

They are square nuts, but they also have a strip of heavy gauge sheet metal attaching them to each-other to help distribute the force. In the past I have tach-welded flange nuts under the floor and that work well.

Gary

**General23cmp** · 08-07-2016, 11:48 AM

Thanks. Interesting. Not sure I'm tracking 100%. Maybe someone has photos.

**General23cmp** · 08-07-2016, 11:53 AM

I found some pics that show it. I'm tracking now. One more question: On the upper 2 bolts. Was there a thick metal strip on the bottom side with the nuts or were the strips just on the 3 flat sections?

**CUSTOM/10** · 08-07-2016, 12:18 PM

Nothing on the 2 top nuts just the 3 straight sections.

Gary

davepl · 08-07-2016, 01:15 PM

Quote:

Originally Posted by General23cmp

The nuts welded to the floor...simple square nuts tacked or some sort of caged nut?

That's why I said "captured nuts" but you said that didn't make sense :-) I think two of mine broke loose or were missing and I had to use a nut, but should have tack-welded a square nut there to be more correct if I cared about that level of hidden detail...

**General23cmp** · 08-07-2016, 02:45 PM

Quote:

Originally Posted by davepl

That's why I said "captured nuts" but you said that didn't make sense :-) I think two of mine broke loose or were missing and I had to use a nut, but should have tack-welded a square nut there to be more correct if I cared about that level of hidden detail...

I said that it did make sense.

davepl · 08-07-2016, 03:10 PM

Quote:

Originally Posted by General23cmp

I said that it did make sense.

I must have read you backwards the first time, sorry about that!

**Eagle9502** · 08-07-2016, 08:18 PM

Any one have pics of the reinforcing strips?

**General23cmp** · 08-07-2016, 08:42 PM

I managed to find some shots of them in the thread below. My question now is how the strips are attached. Are they tacked in a few spots or welded all around?

http://67-72chevytrucks.com/vboard/s...ghlight=Tunnel

**General23cmp** · 08-07-2016, 10:40 PM

Eagle sniped the hump I was watching (link above)! I was drafting him a PM when you posted that you were interested. No worries.

**Eagle9502** · 08-08-2016, 10:53 AM

Sorry about that, I thought you were posting the link just to reference the picture. See my reply on that post.

**General23cmp** · 08-08-2016, 10:57 AM

No worries. I should've been quicker on the trigger. It's all yours. I'm looking for the whole package if I can get it (but plates and hump), so I really don't need to split it up.

08-06-2016, 08:39 PM	#1
General23cmp Senior Member Join Date: Mar 2016 Location: Athens, AL Posts: 360	Hump fastener/hardware size? What size are the bolts, including length? Do they have flat washers on both sides? Lock washer? Maybe they're sheet metal screws?

08-06-2016, 09:12 PM	#2
davepl Registered User Join Date: Aug 2006 Location: Redmond, WA Posts: 6,334	Re: Hump fastener/hardware size? Captured nuts, if I recall, probably 5/16x3/4 bolts as a best guess. __________________ 1970 GMC Sierra Grande Custom Camper - Built, not Bought 1969 Pontiac 2+2 427/390 4-speed Coupe 1969 Pontiac 2+2 427/390 4-speed Convertible

08-06-2016, 09:27 PM	#3
General23cmp Senior Member Join Date: Mar 2016 Location: Athens, AL Posts: 360	Re: Hump fastener/hardware size? That really makes sense. Didn't consider the difficulty of fastening with loose hw.

08-07-2016, 01:01 AM	#4
General23cmp Senior Member Join Date: Mar 2016 Location: Athens, AL Posts: 360	Re: Hump fastener/hardware size? Can anyone confirm the size? Also, the captive nuts, are they just square nuts welded in, or are the "fancier kind" with a cage around them?

08-07-2016, 01:29 AM	#5
Blue/72 Senior Member Join Date: Aug 2014 Location: Sandy, Oregon Posts: 2,381	Re: Hump fastener/hardware size? I have a set I will check size tomorrow __________________ My dad always says that HEI distributers are pointless... •1972 Custom/10 Deluxe. My first truck and I've had it since I was 7. Tilt, tach, AM/FM, 350, deep dish rally's, original paint and an increasing amount of NOS jewelry. It's always taking my money.. •1967 c10 with tach, dropped 3/5 on deep dish rally's •1972 Cheyenne Super. Sold

08-07-2016, 06:52 AM	#6
CUSTOM/10 Senior Member Join Date: May 2003 Location: Sandown, NH Posts: 2,857	Re: Hump fastener/hardware size? I just did mine yesterday, 10 - 5/16-18 thread x 3/4" washer head bolts. This is what's on the original installation with the nuts welded under the floor. The capture nuts should work good if your adding a high hump. Gary __________________ Gary 72 SWB 4x4 My 72 SWB Build http://67-72chevytrucks.com/vboard/s...d.php?t=259859 Last edited by CUSTOM/10; 08-07-2016 at 12:27 PM.

08-07-2016, 11:01 AM	#7
General23cmp Senior Member Join Date: Mar 2016 Location: Athens, AL Posts: 360	Re: Hump fastener/hardware size? The nuts welded to the floor...simple square nuts tacked or some sort of caged nut?

08-07-2016, 11:45 AM	#8
CUSTOM/10 Senior Member Join Date: May 2003 Location: Sandown, NH Posts: 2,857	Re: Hump fastener/hardware size? They are square nuts, but they also have a strip of heavy gauge sheet metal attaching them to each-other to help distribute the force. In the past I have tach-welded flange nuts under the floor and that work well. Gary __________________ Gary 72 SWB 4x4 My 72 SWB Build http://67-72chevytrucks.com/vboard/s...d.php?t=259859

08-07-2016, 11:48 AM	#9
General23cmp Senior Member Join Date: Mar 2016 Location: Athens, AL Posts: 360	Re: Hump fastener/hardware size? Thanks. Interesting. Not sure I'm tracking 100%. Maybe someone has photos.

08-07-2016, 11:53 AM	#10
General23cmp Senior Member Join Date: Mar 2016 Location: Athens, AL Posts: 360	Re: Hump fastener/hardware size? I found some pics that show it. I'm tracking now. One more question: On the upper 2 bolts. Was there a thick metal strip on the bottom side with the nuts or were the strips just on the 3 flat sections? Last edited by General23cmp; 08-07-2016 at 12:14 PM.

08-07-2016, 12:18 PM	#11
CUSTOM/10 Senior Member Join Date: May 2003 Location: Sandown, NH Posts: 2,857	Re: Hump fastener/hardware size? Nothing on the 2 top nuts just the 3 straight sections. Gary __________________ Gary 72 SWB 4x4 My 72 SWB Build http://67-72chevytrucks.com/vboard/s...d.php?t=259859

08-07-2016, 08:18 PM	#15
Eagle9502 Senior Member Join Date: Dec 2015 Location: Brooklet, Georgia Posts: 839	Re: Hump fastener/hardware size? Any one have pics of the reinforcing strips?

08-07-2016, 08:42 PM	#16
General23cmp Senior Member Join Date: Mar 2016 Location: Athens, AL Posts: 360	Re: Hump fastener/hardware size? I managed to find some shots of them in the thread below. My question now is how the strips are attached. Are they tacked in a few spots or welded all around? http://67-72chevytrucks.com/vboard/s...ghlight=Tunnel

08-07-2016, 10:40 PM	#17
General23cmp Senior Member Join Date: Mar 2016 Location: Athens, AL Posts: 360	Re: Hump fastener/hardware size? Eagle sniped the hump I was watching (link above)! I was drafting him a PM when you posted that you were interested. No worries.

08-08-2016, 10:53 AM	#18
Eagle9502 Senior Member Join Date: Dec 2015 Location: Brooklet, Georgia Posts: 839	Re: Hump fastener/hardware size? Sorry about that, I thought you were posting the link just to reference the picture. See my reply on that post.



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08-08-2016, 10:57 AM	#19
General23cmp Senior Member Join Date: Mar 2016 Location: Athens, AL Posts: 360	Re: Hump fastener/hardware size? No worries. I should've been quicker on the trigger. It's all yours. I'm looking for the whole package if I can get it (but plates and hump), so I really don't need to split it up.

Register or Log In To remove these advertisements.