I would like to share a few things about 1st gen seats I've learned. Thought I'd just make a fresh thread so it might be easier to see :-)

2 door seats and 4 door seats can be interchanged with a little work. The brackets that mount seat back to seat bottom are different between the 2, but can be swapped as needed. As expected, the only difference is that 4 door seats are rigid, and 2 door seats fold forward to allow entry/exit from the rear seat. Those brackets are on the outboard side of the seat, where the lever is that you pull up on that reclines the back. You will also need to swap the plastic trim over that bracket too, so save the old ones when you make swap.The bottom brackets that mount the seat bottom to the floor are designed to shift the seat 1 1/2" toward the center of the car. I've seen several of the drivers side bottom seat mounts break at the back on the inside ...seems to be a weak spot there. You can, in fact, mount the entire passenger seat with its bottom bracket on the drivers side, it will shift the seat 1 1/2" to the outboard side, and have the reclining lever on the inboard side. The door will shut tho, and the sitting position isn't too difficult. Power seats were on Olds, Buick, and Caddy J-Bodies. They will bolt right onto your Chevy & Pontiac models. The power systems have a height adjustment which is very useful!! Just need a hot and ground to hook up to the power unit under the seat. One interesting thing of the power seats , is that they have a 1/2" plastic shim between the power bracket and the seat base. This makes the bolts that mount the power base longer than their standard non power counterparts. And yes, you can take your stock seats out, unbolt the non power bottom seat brackets, and bolt up power seat units on your old seats. There is a small metal bracket that holds the plastic trim ( this is what the power switches are screwed into) you will need drill a couple of holes in your stock seats to screw the sheet metal screws in to hold that small metal bracket. You will notice the factory punched indentations to drill the holes at on the non power sear bottoms, the are hidden under the material, but in the same place. I have not run into any power seats on the passenger side, only the drivers side.
I know this may be a bit confusing, but if you have the seats out and look at it for a few minutes you'll see what I'm talking bout. Hope this information is useful to someone out there. Just wanted to give a little back:-)

I just finished the seat swap in my 84 Pontiac. Donor seats came out of 1985 Oldsmobile Firenza 4 Door. Ran into a mess with the rear seats.....something I wasn't expecting. Turns out that the rear seat back and cushion are wider in the 4 door than the 2 door. I had finally , actually cut the reinforcement rods on the sides of both out with a dremel tool. Also had to cut out more of the bottom metal straps on the bottom of the seat back to allow the seat belt bolts to access the their threaded anchors. I'd say I extended the factory holes about an extra inch upwards. Seems the seat back is a bit taller too, but I managed to massage it in place and catch the 3 fingers on the back that catch the reinforcement rods and hold it in place. You really have to cut on the seat cushion because that thing will bow up in the middle when you just try to muscle in in!! When I did the rod cuts, I just removed them and left everything else intact, the foam will squeeze and make a nice snug fit. Hope this helps someone out there!! :-)

Hi Orlen,

Any Pictures of the finished product?

Naa no picts. Nuthin' special anyways, but I do got a power drivers seat now and everything matches up.
Now that I got the seats in, tho, she's crying for a tilt steering column! Thank goodness my local haunt has a few of those left, so I'll be pulling one the first on next month.
I pulled a power rack & pump a couple of weeks ago out of an '85 Cavalier 2.0....OMG...I think they tried to build the darn thing around it I finally got it, but she didn't come easily!! I fell so sorry for the V-6 folks out there!!

Orlen, Just make sure that it is the correct rack, the Cavalier had two styles. With sport steering (Type 10?) and normal power steering. It is a lot of work if you don't have the correct one.

I have a spare set of front seats for my 84. I put a replacement set in from an 86 and the newer seats want to swing forward after sharp stops. Any idea how to fix that?

I found that the ones I have , don't lock easily too. I did notice that they would lock in the upright position when I was moving them around before I got them mounted in the car. I'm guessing they lock up in a crash situation. When they do lock tho, you have to use that button on the back to make them swing forward again.

You could try swapping those outboard brackets off of the origional seats on the ones you have in your car now. That is the part that would do the locking in the upright position.