Just curious,

could the stock transmission be swapped for a newer one or better automatic?

Mine needs to stay auto due to me having knee problems.

Any recommendations?

 

your only requirements are
"automatic" and
"newer or better" and
"into this car" assuming 1984 Trans Am.

Is yours broken? Looking for more performance? Has it been rebuilt before?

The obvious choices for a 1984 L69 Trans Am are 700-R4 or maybe 200-4R. Unless you're using it at the strip and don't give a crap about mileage or highway rpm, in which case the TH350 / TH400 become options which aren't newer and only the TH400 is "better" in torque capacity.

Getting outside of that, newer transmissions with electronic controls such as the 4L60-E and 4L80-E are certainly able to be used, but become a costly swap with the addition of a control computer. There are benefits of having an additional computer but usually not for someone who just wants "newer, better" in a car with no further explanation.

I've had a number of 700-R4 and 200-4R transmissions in a car of mine and based on driving characteristics, I'll take the 200-4R. The physical hard parts are stouter in the 700-R4 but I'm more interested in less abusive hgihway manners than seeing what I can break on a regular basis, so I don't care much about that.

Your car can take a later 88 to 92 700-R4 with no other changes to the vehicle. A minor wiring change allows the 93 passenger car one to work.
With a new longer driveshaft & a crossmember to accommodate the torque arm, you could go with a 200-4R. When going with a non-electronic controlled trans. such as these two, it's best to get a valvebody or whole core from a performance model. (long story short, a 90 truck 700-R4 isn't going to shift or drive as nicely as a 91 L98 Camaro 700-R4. And a 1988 Caprice 200-4R isn't going to drive as nicely as a 1987 Monte Carlo L69 200-4R.)

 

Basically correct, except that the 200-4R is not better if you're running mild gearing in the axle. The deep first gear is more important than the RPM drop on the up-shift to second, which is mostly an on-paper issue anyway, not real-world. Also, the '93 700R-4 in the pickups is no less swappable than the '93 car version. I wouldn't bother with a 4L60E, 4L65E, 4L70E, 4L80e or 4L90E. If you're going to invest a couple thousand dollars into a transmission controller, then go right for a 6L80E. And plan on mild axle gearing around 3:1. The 4L60E is just a 700R-4 with a computer-controlled valve body, then the 4L65E is a bit stronger, and the 4L70E is stronger yet. The 4L80E is likewise an evolution of the TH400, but with a 0.75:1 OD added to the lame 2.482:1 first. The 200-4R has a slightly better first gear at 2.741:1, and the 700r-4 has a very good 3.059:1. The 6L80E / 6L90E have a too-deep 4.027:1. OD for the 200-4R is 0.674:1, the 700r-4 is 0.696:1, and the 6L80E is 0.667:1 in sixth, and 0.852:1 in fifth.

 

93 trucks were 4L60-E.

What happened to your "Option 2 305" build?