not encouraging...
http://honda-tech.com/zerothread?id=1290226

looks like you're better off putting a CR-V b20 block with a gsr head into the prelude. the prelude block looks like a nightmare to vtec.
http://honda-tech.com/zerothread?id=410899

i know there's info about putting a complete gsr into the 3rd gen lude, i found it before. i'll see if i can track it down for you.