It’s gonna happen but not sure if recessing the seats into the floor would be a better option than sectioning the seat structure. I need about a 2” change in height.
What did you do ?

This is what I’m working with

I'm surprised you have to lower the seats. Seems to me like most modern cars the seats are really close to the floor. Is you E body floor that much higher than my 68 B body floor? I put modern seats from a car in mine and we had to add height to them. If you need them to be lower, I'd vote for modifying the seat and not the car. Maybe you are using SUV or Truck seats?

What are they out of ?

Are they power? I ran mine all the way down. It helped. With the height but if I was tall. I'd lower them in the floor.

These are out of a 2019 challenger and they are way higher than stock barracuda seats.

2019 challenger

The drivers side is power but the passenger is manual. I’m only 5’8” and without mods they sit way up

I cut about 2” out of the base and i also had to modify the floor some

After I shortened the base I bolted the flanges back to the slides and tack welded them onto the base, took it all apart and welded it up.
Passenger side is done

I've heard that the new challenger seats require extensive modification to fit. The E body doesn't leave a lot of room under the steering wheel. A smaller wheel or tilt column can help. I went with seats from a 2006 Tiburon and they seem to fit really well and are very supportive. I'm 6' 2" 225lbs,

While I have not done this, take a look at mid 70's into the mid 80's Porsche 911 seats. They have a bit of an e-body vibe to them. I think these might make for a good swap.

They look good ! If I ditch these I have I’ll look into it

Yeah, indeed, they look like a nice 'period-correct' upgrade!

I'm curious: what does a set of nicely finished seats like that cost these days?

I put Supra seats in my '74 Challenger. Had to fab the mounts to get them to sit level as the Toyota floor was flat and the Challenger floor does not. Used a piece of 1" square tube I welded to the seat track, added studs to it to align with the OEM holes in the floor pan. Bolted it in. All adjustments on it are manual, so no problem with wiring in electrical.

I just put 2012 Chrysler 200 seats in my 65 B. Had to take just about 2" out of the seat mounting legs , but not all 4. I just put the seat uo in there sat in it and looked at it . Had the wife sit in and looked at it from out side. . before this I set the power settings in the middle . I cut an inch and then 2 inches . Felt it looked right. welded up some 1/8" plates for the bottom of the legs, marked out on the floor and welded some 3/16 plate to the floor at each leg. The front outer lined up with the factory brace and hole .