this was an HPE I bought for spares some while back with dcoe fitted, I was going to transfer it all into my car but decided it looked too far from original and not very tidy, also the car had very bad low rev flat spots and I wasn't sure I'd ever sort it out it was crazy tyre smokin' when it was on cam though.....
http://lancisti.net/photopost/showgallery.php/cat/677The DCNF fits directly on the original manifold but is very slightly larger in most dimensions except there is no auto choke sticking out the side!
The other problem with the dcoe was that the air intake is very close to the front slam panel (a smaller radiator has to be fitted to allow enough space) the car had a foam filter but I felt it was too tight for space I think a custom made air box would really be needed. As regards the standard carb I think I would look to use the original adaptor from the top of the carb and add a different feed to that with a remote filter however I felt that it was better not to get too ambitious and I was also slightly concerned about carb icing in colder weather it's up to you of course but modification can become a never ending chase for the holy grail that's why I changed direction and because I don't have the skills knowledge and ability to do a lot of it properly