Cam belt advice 
  Hi all
 
 Fitted new cam belts today to my 4v. (888)  I set the tension to allow 5mm of deflection between the camshaft pulleys.  I've read elsewhere that they tighten with the engine's heat (...is this because the pulleys expand?)  If so, I expect they'll soon be stretched, so at what mileage should they be checked again for tension?  And how long do I keep the revs down -  I'm presuming the belts need to 'bed in'?
 
 Cheers