ClassicCar

On removing and replacing the tranny, I've found it much easier on the back to do it from the bottom (you still need to remove the floorboard panel, to get good access to the upper bell housing bolts). Taking it out the bottom does mean the car has to be jacked a bit higher so you can get the tranny-bellhousing assembly out from under the car. As for installation, install 3" pilot studs in the two topmost bell housing bolt holes in the block. That'll be a really big help in aligning the mainshaft to the clutch. Use a good shop jack or rent a transmission jack to lift and support the tranny-bell housing assembly. Much easier that way to get everything lined up and slide it into place. And one final tip ... use some wire,string or a spring to hold the clutch lever on the bell housing in place so the throwout fork in the bell housing is all the way back. Then as you work the tranny forward, watch to be sure the throwout bearing is properly aligned with the fork. This is pretty easily seen from the bottom.

As for the peripherals, one non-original thing I recommend is to place the kickdown switch not under the accelerator pedal, but so that your left foot can find and depress it. You'll be surprised how often you'll find yourself around 30 mph, in overdrive, and wanting to accelerate mildly. It's nice to just tap the kickdown with your left foot rather than having to floorboard the throttle. Everyone I've done this for (including me!) has loved it.

Look for a 1951 Hornet or first series 52 rear assembly, Auto-matic, 3:51 ratio and just bolt it right in. Better than overdrive. If you want more speed, bolt in second series 52 Hornet DANA rear, same as 53 and 54, 3:07 ratio and drive 80 all day with great gas mileage. Walt.

I agree with Tallent R., and remember well my discomfort starting out on a hill in my former '51 C8 coupe with stick shift and 3.07 gears. The 3.07 was fine for the Hydramatic cars it was designed for, which had a lower first gear, but can sometimes be a bit daunting with a 3-speed stick.

Having had it both ways, I conclude it's really a matter of personal preference plus the kind of terrain one usually has to deal with. My (originally) "stick but no OD" Hornet had a 3.58 gear set when I bought it, and I found it was a really nice all-around ratio for driving hilly north Georgia. (I always thought it should have been the standard factory gear for the non-OD Hornets, but I guess they wanted to be sure they could match or beat the Olds 88s from a stoplight). So I agree the 3.58 is a good compromise if you want to keep things simple and not deal with the governors, solenoids, etc. of the overdrive approach.

But out on the open road, many folks using the 3.58 feel like the car needs one more gear. The OD approach gives you the better solution performance-wise, albeit with the extra complications. With OD you get the good start-up gearing and also a great cruising gear with the OD engaged. I installed OD in my Hornet and at first left the 3.58 gears in place. I found the car was a bit over-geared, with some of the more challenging hills requiring dropping out of OD, even at Interstate speeds. I first thought I might go with the factory stick-shift ratio of 4.10, which gives you a nice top gear in OD of about 2.87. But I wanted to do just a bit better than that, so installed the later ('52-'54)Dana axle, which has more available gear choices, and went with 3.73 gears. This has turned out to be just perfect. It seems the difference from 3.58 is pretty minor, but it moves the engine's operating speed and HP up enough to make a pretty dramatic difference in taking the hills. For my combination of local driving in moderate hills and long-distance trips on the Interstates, this has turned out to be an ideal arrangement.

So it's all a matter of what you really want, and how much hassle you're willing to undertake to get there.