Help Adding Rear Seat Belts

[Poppy's 55]

So I took out the back seat and I am trying to figure out where exactly to add the fastening bolts for 3 sets of belts.

 

I'm sure someone has already done this so advice would be awesome and pictures would be even better.

 

Thanks

 

PS. I know I need to clean up under there

[Beemon]

I would look for a frame mount and then brace/reinforce the body. Bolting seat belts in without a solid footing can be disastrous in the event of something ever happening. 

[old-tank]

Cut the mounts out of the floor of a modern car and use those under your floor.

[EmTee]

Get a set of these for each side...

 

https://www.summitracing.com/parts/aul-9871?seid=srese1&cm_mmc=pla-google-_-shopping-_-srese1-_-autoloc&gclid=EAIaIQobChMIvPvlwPqC3AIV0sDACh0Orw0wEAQYAyABEgL5A_D_BwE

 

Edited July 3, 2018 by EmTee
clarification (see edit history)

[56 Buick]

I am interested in this as I plan to fix rear lap belts to the rear of a 56'.

 

I suspect your hoping someone who has already fitted seat belts will chime in with the exact positions they put the drill through?

 

Anyway I would think you can also buy strengthening plates to sit under the body floor pan. The principle being the stress or pull is spread across a wider portion of the floor pan and be less likely to pull through.

[Poppy's 55]

4 hours ago, 56 Buick said:

I am interested in this as I plan to fix rear lap belts to the rear of a 56'.

 

I suspect your hoping someone who has already fitted seat belts will chime in with the exact positions they put the drill through?

 

Anyway I would think you can also buy strengthening plates to sit under the body floor pan. The principle being the stress or pull is spread across a wider portion of the floor pan and be less likely to pull through.

 

That's exactly what I was hoping for but I guess I'm out of luck. I will return with info on my project for your reference.

[56 Buick]

Thanks.

 

I note I have also attempted to find something on the internet without much luck.

 

[Machine Gun]

22 hours ago, EmTee said:

Get a set of these for each side...

 

https://www.summitracing.com/parts/aul-9871?seid=srese1&cm_mmc=pla-google-_-shopping-_-srese1-_-autoloc&gclid=EAIaIQobChMIvPvlwPqC3AIV0sDACh0Orw0wEAQYAyABEgL5A_D_BwE

 

That's exactly what I've used on all of the cars I've added seat belts to.

[Poppy's 55]

8 hours ago, Machine Gun said:

That's exactly what I've used on all of the cars I've added seat belts to.

 

These are exactly what I was going to use, although I was getting them from Juliano's Hot Rod Parts, but what I really wanted to see was where exactly folks were mounting them.

[EmTee]

When I added them to my '64 GP I saw that there were dimples in the floorpan which seemed to identify where the optional mounts would have been installed at the factory.  The key thing is that the anchor point is just above where the floorpan kicks up at the seatback.  Space as far apart as possible in the seating position BUT -- be sure that the anchor plates do not interfere with any reinforcement channels on the underside of the floorpan.  The second photo below gives you the idea of where the anchors would be located.  That photo was taken before I installed the anchor plates shown in an earlier post.

Edited July 5, 2018 by EmTee
typo (see edit history)

[56 Buick]

On 7/5/2018 at 10:23 PM, EmTee said:

When I added them to my '64 GP I saw that there were dimples in the floorpan which seemed to identify where the optional mounts would have been installed at the factory.  The key thing is that the anchor point is just above where the floorpan kicks up at the seatback.  Space as far apart as possible in the seating position BUT -- be sure that the anchor plates do not interfere with any reinforcement channels on the underside of the floorpan.  The second photo below gives you the idea of where the anchors would be located.  That photo was taken before I installed the anchor plates shown in an earlier post.

So I am assuming the mounting points for the rear seats should be level with or just below the level of the top of the rear seat base. That way when under stress the belt will not crush/foul/move against the rear seat.

[EmTee]

Judging from mine, probably a little lower than the seat top.  The belts will be routed up the backrest and out over the lower seat cushion.  The seat cushion will be compressed when occupied and the belt is being worn. The reinforcement plates should be installed horizontally (or nearly so).  The bottom edge of the plate should be just above the point where the floorpan goes from vertical to horizontal.  That will determine the height of the hole above the floor.

 

By the way, I don't know if you have belts yet, but I bought mine from CARS (http://www.oldbuickparts.com/index.php).

Edited July 8, 2018 by EmTee (see edit history)

[56 Buick]

Thanks for that.  Did you tac weld the backing plates onto the underside of the car body or are they merely sitting freely?

[EmTee]

Drilled a 3/16" hole in the plate and tacked it in place so it wouldn't spin when tightening the bolt.