Early/late seat swap: Can't anything be simple?

69427

69427

The Artist formerly known as Turbo84
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Mar 30, 2008
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Clinging to my guns and religion in KCMO.
In my quest to further reduce left side weight bias I pulled the driver's seat out of the '69 and was working to install one of the '79 seats I got from Karsten. I weighed these and my stock seats a while back, and the later versions were each about 10# lighter. But, (and call me naive :bonkers:) it wasn't a simple matter of undoing four bolts and then tightening these same four bolts. It appears that Chevrolet changed the brackets to different length and different shape over the years. I haven't pulled the brackets off the '69 seats to see if they would fit the '79 seats, but I'm speculating that the bottom cushion design differences precludes this interchangeability.
Looks like if I'm going to have to weld up something, I might as well do it in aluminum. The steel '79 brackets are 6# total, and I might be able to shed another couple pounds doing them in aluminum.
 
Yeah, the floor pans changed, later cars don't have the tubs for the seats either. Even funnier, the 78-82 cars w/ a power dr. seat have a different floor than the non power ones. The power seat floor is much deeper.
 
Twin_Turbo said:
Yeah, the floor pans changed, later cars don't have the tubs for the seats either. Even funnier, the 78-82 cars w/ a power dr. seat have a different floor than the non power ones. The power seat floor is much deeper.
Click to expand...

Oh really?? interesting, in that can you gimme a height/depth difference so maybe I wonder about lowering my seat further even....

be nice to get another 2" lower....

:yahoo: I think if the frame is the same between '72 and '80 for instance, in the mid section where the bird cage sets....I can fab up some sort of change...

if the factory did it, and no one scrapes their ass, certainly my ass should be good, I hope....

:bonkers::waxer:
 
?? seat frame is different, floors are different, hole locations different, seat bottoms different, nothing really interchanges.

Your car has fiberglass floors, if you want to drop it you have to cut the floor
 
Twin_Turbo said:
?? seat frame is different, floors are different, hole locations different, seat bottoms different, nothing really interchanges.

Your car has fiberglass floors, if you want to drop it you have to cut the floor
Click to expand...

Been cut for some 8? years, moved the firewall forward to drop the pedals and get my knees off the wheel, straighten my legs out...HUGE improvement for ME at 6'5"...but would really like another two inches off seating height....

and from years ago, I really liked the later C3 seats as opposed to the early seats....

had NO idea of any height differences....

:flash:
 
I still have one of the seat tracks - I think it's the driver's side.... you should have no problem to cut and re-weld to make it fit but height might be an issue.
 
69427 said:
In my quest to further reduce left side weight bias I pulled the driver's seat out of the '69 and was working to install one of the '79 seats I got from Karsten. I weighed these and my stock seats a while back, and the later versions were each about 10# lighter. But, (and call me naive :bonkers:) it wasn't a simple matter of undoing four bolts and then tightening these same four bolts. It appears that Chevrolet changed the brackets to different length and different shape over the years. I haven't pulled the brackets off the '69 seats to see if they would fit the '79 seats, but I'm speculating that the bottom cushion design differences precludes this interchangeability.
Looks like if I'm going to have to weld up something, I might as well do it in aluminum. The steel '79 brackets are 6# total, and I might be able to shed another couple pounds doing them in aluminum.
Click to expand...

I mounted a set of C-5 seats in my 69 and after I noticed the original tracks needed to be modified, I looked for another option. A salvage yard Geo Metro donated its tracks and they were modified to mount the C-5 seats and retain forward adjustment. The seats are now a little closer to the floor than original. Tracks cost $20, time spent modifying, priceless.
 
I just put 78-82 seats in my '71. I used the 71 tracks that I had to do some minor mods to. Just had to weld a U-shaped bracket to the front. The rear attachment between seat-and-track was fine.

The new seats are great. Low to the floor and at 5'10" I have several clicks left before the seat is all the way back.
 
I have had '82 non power seats in my '69 since '83, they have never been bolted in back.
I always felt that the seat belt would prevent the seat from unwanted movement.
Thought of using aluminum plate bolted too the back of the later seat track with an offset hole bolted to the original '69 rear seat mounting position
Always nice to have suggestions from someone who has personal experience.
 
If you're more concerned with weight than C3 correct ( I "think" you are just a touch weight obsessive? :wink:), Mazda Miata seats will fit. Over on CF there's actually a member offering the template I believe to make the mounts... I can't imagine there's anything lighter this side of a Kirkey aluminum.
 
I haven't whipped up the conversion brackets to bolt the original sliders to them, but I pulled a set of 1st generation Nissan 240SX seats out of a Porsche 944 at a junkyard a while back. Comfortable, supportive, simple, and light. And they fold forward, which is a plus.
 
I recall you're looking at keeping the car "street" worthy. But have you considered Kirkey Seats? Not cheap but huge weight savings. Heck a gutted C3 seat weighs over 30#. The Kirkeys come in under 20# - you cut a heap of weight if do both sides!

Here are a bunch of pics to consider:
https://www.google.com/search?q=cor...n7TOAhVMSCYKHVGzA_gQ_AUICSgC&biw=1366&bih=604

I'm having a bit of a challenge getting mine in as I've pushed the engine aft 13" and that narrows the cockpit quite a bit. [Probably should have shifted it a bit into pax side - oh well.]

Cheers - Jim
 
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phantomjock said:
I recall you're looking at keeping the car "street" worthy. But have you considered Kirkey Seats? Not cheap but huge weight savings. Heck a gutted C3 seat weighs over 30#. The Kirkeys come in under 20# - you cut a heap of weight if do both sides!

Here are a bunch of pics to consider:
https://www.google.com/search?q=cor...n7TOAhVMSCYKHVGzA_gQ_AUICSgC&biw=1366&bih=604

I'm having a bit of a challenge getting mine in as I've pushed the engine aft 13" and that narrows the cockpit quite a bit. [Probably should have shifted it a bit into pax side - oh well.]

Cheers - Jim
Click to expand...

I looked at a few pictures of Kirkey seats. I'm used to seeing them in sprint cars and stock cars, but it looks like they've got a couple models that might look reasonably at home in a street car. The big problem at the moment is the $/Lb weight reduction. I currently have some lightweight '79 seats I got from Karsten. Going from memory I believe they are around 25# each. I'm thinking I'd have to make my buying decision on the support that the Kirkey seats would provide, as the cost just to take some weight out is probably out of my budget. But, nothing stopping me from keeping my eyes open for a sale/bargain/used seat.
 
Ahhh yessss. But you CAN Weld! Oh - look out - I see a SLIPPERY SLOPE AHEAD!

Many of the "layouts" are near engineering drawings - or could be cardboard prototypes.

I bet you could get to sub10 on each seat - with lower seat tracks installed!
Put in a harness bar, a 5-6 point harness....That works out to +3 HP equivalents!


Cheers - Jim
 
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