27" v 700c

bit of a noob question…

ok, i’m aware that there is a slight difference for these two size specifications, but are track frames/forks specific to one or the other?

and is one size generally more desirable than the other? 700c parts seem to be more abundant.

You could put 700C into a 27" track frame. BB will drop a few mm, slightly increased clearances will allow more wheel movement towards the seat tube for gear selection or larger tyres overall. Bigger tyre selection for 700C than 27". Going the other way will reverse all this.

If it was built for tubulars, they’re the same size as 700C.