As others have already said, yes. Now, I'll stretch this statement a bit further:

My 64 Raleigh Gran Sport came with steel 27x1-1/4 wheels. As was my habit in the old days, I immediately replaced them with a set of 700c tubular wheels, and of course loved the difference.

Six months later, I get this Gitane Tour de France, minus wheels. To get it on the road, I transfer the wheels from the Raleigh to the Gitane.

Now, due to some other dealings, I've got a set of 27" clincher wheels on the rack, narrow (1/2" cross section) Weinmann rims. I put on a set of 27x1 - 110lb pressure tyres on them, and I'm not losing too much performance vs. the tubulars. They're way better than classic 27x1-1/4s, I just dread the thought of getting a puncture on the road. Those tyres were a real pain to get on.

So it is easy to get like performance between 27" and 700c wheels - if you're ready for a few tradeoffs.

Syke
Deranged Few M/C