thanks.. i think 400's had the same heads but the ra models. its the wq code and extra stuff added to the 400 that makes it different. mine is a M21 the codes are on the pass side back towards the tail housing near the drain plug. here are some pics of the heat riser.. just got my parts back. I still i hate doing the rope seals. every time i cut them wrong its always a 2 time process for me. I quess i'm doing a flat tappet cam again. there was just too much sh--t to change for a roller. oh well thats the way it goes.