i remember on my r32 i cleaned it out once, but it was not part of the rail...on the r33 i am not sure. installing one though, just remove the old one and put in the new, if it is electronic then i wouldnt try it, i would be replacing all the efi full line while i did it too, to make sure that nothing happens. as for placement, dont make it too far away, prob on the firewall. to tune it you will need a dyno prob, or trial and error. The original fuel reg is located inbetween the plenum and the tapper cover i think.