Newbie questions about aftermarket seats in 68 coupe

[heySkippy]

Why can't anything be simple? Let me preface this by saying this is the first old car I've had since I was young and I'm 61 now. There's much I don't know.

I have a 68 coupe that came to me with generic racing seats. I want to get them out temporarily to work on the carpet, but looking at the way they're installed has me asking more questions before I even start. They're on what I assume are aftermarket rails that are bolted to the floor. The bolt head is in the rail and under the car are 4 holes on each side to access the nut. Up inside these holes I can see the nuts at the other end of the bolts.

These bolts and nuts appear to be tragically weak. I don't see much more than a single thickness of floor pan metal between them and it looks like the seats would break free easily in a crash. I contrast this to the mounting points that were built for the harness with 1/4" steel plates backing the bolts under the car. Is this the way the original seats were mounted?

Also, the bolts for the seat rails don't match what appear to be the original holes. New holes have been drilled for each. In at least a couple cases the new holes are far enough off center with the big hole that getting a socket on them is going to require a u-jointed adaptor. Was this really necessary? Do aftermarket seat rails never line up with stock holes?

So, I think I can get these seat rails unbolted and out of the car so I can work on the carpet. Once I've done that should I put it back the way it is now? If not, what are my alternatives?

Lastly, I read in another thread a reference to lowering the seat pans. How difficult (expensive) is this to do? I like these seats well enough and would hate to go back to a non-bolstered seat, but they do sit high.

Thanks in advance. Pictures follow.

 

[Boom]

Thats pretty much teh way the stock seats are mounted. They had a fancy nut on the underside.

I'd be more worrired about that power cable running along the frame rail myself

 

[msell66]

Lowering the seat pans is not complicated, just time consuming. Weld cutter bit, air chisel, cutoff wheel or saw and a welder.
That exposed cable...

 

[heySkippy]

If someone has the time to educate me, what should be done with that battery cable?

 

[msell66]

If someone has the time to educate me, what should be done with that battery cable?

Run it inside the car. Running it under the kick plates is a good place.

 

[Horseplay]

Those are nice subframe connectors. Look to be Tin Man's. That cable is not only routed poorly it looks potentially undersized as well. As Mark suggests best to route within the cabin through the door sill.

The floor bolt set-up appears to be fine. The nuts used look to be metal locking type that should not be reused. Get new nuts and you're good to go.

 

[stangg]

The floor bolt set-up appears to be fine. The nuts used look to be metal locking type that should not be reused. Get new nuts and you're good to go.

Did you look closely at the fourth picture? The washer isn't even seated. The underside of the seat riser has a double layer of steel where the lower strip has a pair 90 degree bends to stiffen the pan. You can see the original hole between the bends, and the new hole is so close to one of the bends that the washer mainly touching the top edge of the bend.

If reusing that hole, I'd think about flattening the bend in that area so the washer can seat properly to the floor. You might also use thicker fender washers if they'll it. I'm sure the grade 5 fasteners are fine, but I generally use grade 8 for seats and belts.

 

[B67FSTB]

Did you look closely at the fourth picture? The washer isn't even seated. The underside of the seat riser has a double layer of steel where the lower strip has a pair 90 degree bends to stiffen the pan. You can see the original hole between the bends, and the new hole is so close to one of the bends that the washer mainly touching the top edge of the bend.

If reusing that hole, I'd think about flattening the bend in that area so the washer can seat properly to the floor. You might also use thicker fender washers if they'll it. I'm sure the grade 5 fasteners are fine, but I generally use grade 8 for seats and belts.

Same here , flatten that reinforment plate , use a bigger and thicker washer , use a new selflocking nut and reroute that power lead. (inside car , under sill for example )
You have probably the battery in the back , so use a fusebox with a big fuse (200amp) at the + pole and connect that lead to that fusebox.

 

[tarafied1]

I did both, lower my seat pans using 69 Mustang seat risers and ran my power cable thru the door sill and into the engine compartment thru the lower A pillar area. Hard to describe but it runs from the battery on the right rear of the trunk over the wheel house into the rocker area on the inside of the interior panel. Then thru the rocker panel under the door sill. It comes out in the kick panel area. I drilled a small hole in the front of the A pillar and used a grommet and the wire runs out and up along the aprons outside of the engine compartment. It comes in just under the starter solenoid. In the pics are just speaker and amp wires which I just ran under the carpet along the trans tunnel. I didn't take any pics of the battery cable routing (sorry)
I cut the old 67 seat risers out and welded in the 69 risers. They lower the seat over an inch. I also moved them back from the original location just a bit since I am 6 foot I am not huge but the extra height and leg room made it much more comfortable. If you go this route you can modify the riser to reinforce it for the modern seats while its apart. I will add that be sure to cover everything when using the die grinder! I have tiny spots on my windshield on the inside from the hot sparks/metal.