This is the part that caught my eye. I understand the impulse. I've got several vintage bikes that I installed new components on, and an '82 Trek should lend itself very well to such an upgrade. That said, depending on which model it is the parts you have could be nice. There are some components being made today that I'll be worried about when they are 30 years old, but the components that were made during that time are built to last. If you decide not to use them, consider cleaning them up and selling them.

Now back on topic, I've got an '82 Trek 614. I'm using 27 inch wheels on mine and it still requires longer reach from the brakes than you get from most brakes from the big three component makers these days. Standard brakes now max out at 49mm of reach. I'm using Tektro R539s on my Trek with 27 inch wheels. These brakes have a range of 47-57mm reach and I think I'm about in the middle of that range. With 700c wheels I'd be at the end and I might even need the longer reach R559's.

The 700 and 900 series Treks from that year were sold with 700c wheels, but if you've got 27 inch wheels now you probably have a 400, 500 or 600 series frame and so I would guess that your brake reach issues would be comparable to mine. As I noted above, there are good brakes available that will make this conversion work for you, but you'll need to look for them. The other thing you should be aware of is that you probably need nutted brakes (as opposed to recessed) or you will need to have your frame drilled out for recessed brakes. I recommend looking for nutted brakes since that is an option for the brakes with the reach you need anyway.

Finally, if you decide to stick with 27 inch wheels for any reason, there's a guy selling a really nice set right now over on the Classic and Vintage sales sub-forum.