Whirly is correct: if it is your first piston type rating it is 5 hours plus test, if you already have JAA piston type ratings it is 3 hours plus test.
The situation only changes when you have 500 hours on type, as Whirly correctly pointed out.
However, that is not to say the CAA won't consider a reduction in training on the recommendation of the Head of Training of the school that does your "conversion".
Some time ago there was a requirement of minimum hours on type to teach, but that is no longer the case.
Edit - Actually, you better check in JAR FCL2 that what I've said isn't because of a UK long-term exemption, in which case Holland may be different
Last edited by mongoose237; 14th March 2006 at 16:50.