first, is there any alphard 200? or did you mean 2004?
secondly, even if the spring fit/compatible each other. i still didn't recommend it since it is not suitable in term of bounce rate, hardness and height. both is different type of vehicle. so not advisable.
The rotary kakis have been one of the largest bunch of cars on the track when it comes to HPC. me and alchemist will be there. anyone else headed there?