Joined: Nov 2016
If you want overdrive, go with the 4R70W. not to step on any toes, but the AOD has issues, unless you spend the money to get rid of its lockup feature and go to a one-piece input shaft. Otherwise, it's just not a great performance transmission, on the top end. They are a ticking timebomb of fail, if you make full-throttle 3-4 shifts with a healthy engine. Also, TV cables suck. With enough work, an AOD can be made to shift crisply, and do about as well as a C4, but with overdrive. In stock form, I have never been impressed.
The 4R70W benefits from a lot of reliability upgrades, and with its asynchronous shifts, it can hit any gear, any time, any RPM if you tell it to. Any of the good controllers (Baumann makes the best) have the ability to store different 'shift modes' that you can easily switch between, too - so you can go from a nice, soft, smooth cushy ride to 'bark the tires as it goes into gear' sport mode. Or whatever other option suits you. Fully programmable. AND you get to keep the lockup torque converter, which will get you a couple MPG out on the highway. Paddle shifters are a common option for these too, though on a classic like yours it wouldn't necessarily be a good option, compared to a vintage steering wheel. Don't let the features bamboozle though: You can keep it very simple, and just enjoy a bulletproof transmission that will handle around 5-600 horsepower in stock form.
Better to do it right, do it once, and not spend the money three times. =)
Four-link rear ends are more expensive, complicated, heavier, and handle worse than a 3 link. They can bind under certain conditions, so they're not great for handling. However, they can be made to plant the rear end really hard on launch, and as such, are often used for drag cars.
For most cars, I'd say 3-link is the way to go if you feel the bug to swap everything out and get fancy. RRS Racing has some great videos of installation on their 3-link, if you want to see what they look like.
I smile a lot. It makes people wonder what I'm up to...