73-87 bench designs - how many are there?

[rgunlock]

I'm restoring a 78 GMC High Sierra and have reached the point where I am ready to replace the foam and recover the bench seat. Bought the foam and cover, then removed the old upholstery to get a surprise. Foam isn't going to work at all. After some research, I think my 78 had a 81-87 bench. Back folds forward and the foam is molded over/around the back frame. Bottom springs are a flat platform for the foam, there are cutouts for the seatbelts, etc.

[rgunlock]

So, my wife found me a bench from a 79 GMC at a pick-n-pull for $50. Totally different from the 1st bench. The back is fixed. It has springs for the bench and just a thin foam that has lips that wrap around the top of the springs. Foam for the back sits in front of the frame, but is formed so that it wraps around the frame at the edges. Pics are after I restored the frame and replaced broken springs.

[rgunlock]

The foam I bought doesn't actually work with either bench. The bottom pad is thick with some cutouts along each edge. The back is thick with a groove at the top that looks like it should fit around a frame, but the back also has some cutout contour around the edge that doesn't work with the 79 back frame.

The back foam could almost work with the fixed 79 back frame but not quite. The seat foam could almost work with the 81-87 seat but there is no reason for the cutouts on the seat edges.

This foam is what you get for 73-80 Chevy/GMC from classicindustries.com as well as from usa1industries.com and probably others.

I was told by one of these vendors that during that time, the "lower-end" models had benches with more spring and thin foam (like the one I've got). The "higher end" models had less spring and thick foam which is what this foam is for.

Anyone seen a bench that this foam would work with? Got pictures of the frame you can share? What year and package did it come from? Thanks!

[bbbc10]

Trim levels had diff style of seats

[USSkoval]

I like this thread! I've always wondered what the differences are under the covers... very good info so far. I think the 80's seats were all the same, the upper trim levels just had cloth instead of vinyl. It would be cool to see the guts of a 70's seat from a high trim level truck. My '79 crew cab is a Silverado trim level (with the vinyl option rather than cloth) and the seats feel like they are constructed like your 70's base trim seat. BTW, my front seat back is stationary and the rear seat back folds.

[TKCR]

Your seat in the first post is a seat from a 81-87. The second seat is a correct seat for the 79. It is really a preference, but I prefer the 81-87. They all fit in the 73-87 trucks, but the tracks have to be correct for the seat itself.

Now that foam you got, it doesn't look like any of the new foam I have purchased for the 81-87. And as you probably know, you can only get the seat bottom. The seat back foam rarely ever needs replacing anyways.

The seat styles & tracks were 73-76, 77-80 and then 81-87.

[TKCR]

Originally Posted by bbbc10

Trim levels had diff style of seats

They had different styles of upholstery, but it's the same seat under the upholstery. There are 3 styles of seat frames & tracks by the model year.

73-76, 77-80, 81-87

When it comes to the foam:
73-80 seats are straight across the lower cushion. The foam are seperate pieces from the frame and they have no pass-thru for the floor belts.
81-87 bench seats have a pinch at the rear of the seat where it curve in. Only the bottom foam is not attached to the frame, the upper portion is non replaceable as it is molded into the rear frame, in some cases.

[rgunlock]

Thanks for the info TKCR. So if I understand you correctly, you are saying that for a given year model, there were not different frames & foam for different trim levels on the truck.

Since the foam I have doesn't work for 81-87, and doesn't work for the 79 bench, are you suggesting that all I have to do (haha - not so easy to find!) is find a 73-76 bench and it will work? Basically I'm thinking a junkyard bench is cheaper than the cost of returning the heavy, bulky foam and upholstery that I already have.

[TKCR]

Originally Posted by rgunlock

Thanks for the info TKCR. So if I understand you correctly, you are saying that for a given year model, there were not different frames & foam for different trim levels on the truck.

Since the foam I have doesn't work for 81-87, and doesn't work for the 79 bench, are you suggesting that all I have to do (haha - not so easy to find!) is find a 73-76 bench and it will work? Basically I'm thinking a junkyard bench is cheaper than the cost of returning the heavy, bulky foam and upholstery that I already have.

There are 2 frames, that I know of. And there are 2 styles of foam. Both are 73-80 & 81-87. Then there are 3 tracks, which is explained in the above post. Now if the foam you got was for the 73-80, then I'm curious as to why it doesn't fit. That might be something you call where you got and talk to them about. I have to admit, I have not ever seen personally, a frame or foam from 73-80. I mainly work with the 81-87 seats, so I am getting to know these seats pretty well.
Now your options could be, keep the 81-87 seat. The foam looks good and you could put a rebuild kit under the foam, just for good measure to firm it up. But if you want a period correct seat in your truck, then I can relate to that. I would call the place where you got the cover & foam from. Maybe they will accept taking the items back in return for a cover for the 81-87.
I really wish someone else can chime in on that other frame, to see if it really is a 73-80 frame. I just can't honestly say for sure, because that maybe the reason why the foam isn't fitting. Send KrazyRay a PM and ask him to look at this thread, and see if he knows this other seat frame. He is someone that is pretty knowledgeable when it comes to these seats. I have asked him some guestions myself, And he can probably help us out.

[USSkoval]

IIRC, the old 70's brochures state that the higher trim levels have a "full foam seat". Why would they say that if they were the same as the lower trim levels? It always made me wonder why they would purposely make a seat that was less comfy than another, when they probably cost the same to manufacture.

[KrazyRay]

The 73-76 frames are different than the 77-80. The 73-76 seat track bolts are about 11 1/4" front to back and the 77-80 are about 17" front to back. The only fixed back seats I have come across are from crew cabs and suburbans. That could be your foam problem. Can you post some pictures of the seat tracks and underside of seat from your 79?

[rgunlock]

Took these before disassembly so I could remember how the springs went back on. Let me know if these don't show what you need.

[tgdoumit]

wow, good info here! if i could ask about something mentioned above... will suburban and truck seats bolt right in to either truck in the square bodies?

[KrazyRay]

That seat came from a regular cab pickup and is 77-80. I will look into foam options.

[TKCR]

Originally Posted by KrazyRay

That seat came from a regular cab pickup and is 77-80. I will look into foam options.

Thanks Ray, I knew you would help. This info will help me also someday.

[rgunlock]

Thanks Ray, I'm interested in whatever you come up with on foam.

TKCR, looks like you got that 74 bench from DA68. Assuming you strip it down for a new cover, perhaps you can post pics of its frame here for comparison. From DA68's pic of the back, it looks like that part of the frame is very close to my 79 seat but appears to fold forward where mine doesn't.

Thanks!

[TKCR]

I had planned on that. I am curious as to what this frame looks like.

[TKCR]

Was able to stop at a local yard today before work. They say that this came out of an 86 C30. Just took a couple of pics of the bottom. I won't have time to strip them down until Sunday, MAYBE.

[TKCR]

And this one, from the same yard, is from a 74 C60. I wasn't expecting to see the risers on the tracks. So KrazyRay, need your input on this one. For the seat to be used in a pickup, the seat will need a different sets of tracks? 73-76 tracks?

rgunlock, I'm not trying to highjack your thread here. But you started a good one that can be helpful for a lot of other people, as far as the different frames.

[rgunlock]

Originally Posted by TKCR

rgunlock, I'm not trying to highjack your thread here. But you started a good one that can be helpful for a lot of other people, as far as the different frames.

As far as I'm concerned, anything relevant to 73-87 bench designs, frames, foam, etc. belong here. I'm like you, I'd like to see a thread benefit a lot of people, not just me (as long as I figure out a way to use the foam & cover I've already bought without spending too much more $$$ )

[KrazyRay]

That C60 seat uses the 67-72 seat tracks because it has a flat floor. If the tracks are good, they are worth a good amount compared to 73-87 tracks. That seat will not work with the 73-76 tracks and you will need to do some fab work for 77-80 and 81-87 tracks to work on it. The medium duty trucks, vans and motorhomes from 73-87 use a lot of "leftover" parts from 67-72. Here's some pictures of 73-76 tracks:

[rgunlock]

Originally Posted by USSkoval

IIRC, the old 70's brochures state that the higher trim levels have a "full foam seat". Why would they say that if they were the same as the lower trim levels? It always made me wonder why they would purposely make a seat that was less comfy than another, when they probably cost the same to manufacture.

Interesting thing if you do a search on "full foam" (and thanks for that tip) it looks like for quite a while, back into the 60's at least, benches were either standard or "full foam". This thread from 60-66 forum has pictures of new "full foam" that looks just like what I bought for my 78.

http://67-72chevytrucks.com/vboard/s....php?p=7757191

[TKCR]

Took one of the seats apart this morning. It has been rebuilt and swapped at sometime, because it was in an 86, and this is not an 86 seat frame. It has the 77-80 tracks and the frame looks like it would take the foam that you (rgunlock) have gotten for your seat.
So it looks like there are more frames that I'm aware of. I will post pics of the other seat frames asap.

[rgunlock]

Yep, that looks like a match for the foam I have. Can't tell from your pictures, but is the back stationary or does it fold forward?

[TKCR]

Originally Posted by rgunlock

Yep, that looks like a match for the foam I have. Can't tell from your pictures, but is the back stationary or does it fold forward?

yes this one folds