There is heaps of fun to be had if you willing and willing to spend the time and $$
Extractors are near impossible to get, we started making them before we put in a different motor, for the short term we stripped back the factory manifold removed the butterfly valve and welded it shut.
You can get side draught manifolds in Japan (I still have mine, including matching tuned dellortos etc, well for that matter the whole motor still :D)
We had a blast, got some good power from it overall. It is a job of patience and time (love)
Know heaps about it, so feel free to ask questions, we rallied ours, have a look on youtube.com/jesusrallysport for some videos and check out jesusrallysport.com for pics from the engine build