I know there are already quite a few posts about it. But I thought a new one to clarify a few things and to tell about my bike might be helpful for the fellow looking for quick answers.
I bought my Norton kit on Ebay for my OIF 76' Bonneville. The hose that comes with it was too big at 3/8" ID. I bought some 5/16 ID transmission oil, but even that seemed too big as the existing old hose was more like a 1/4". Anyhow, sliding the stock hose on the filter housing IN pipe and the new hose on the OUT pipe was very difficult ( since there are made for the 3/8" hose size ), even after softening the hoses in boiling water. I got 2 nice blisters to show for it now. I had to connect the hoses before securing the whole thing under the swing arm, as it is really cramped in there. I used a 3" muffler clamp to secure the filter housing around the frame. I put some clear tubing around the U-shaped bolt to protect the frame.
The filter that came with the kit has a Fram PH2839 that is not available for sale in the US. It is a European market filter only. I found the Wix 57013
which is a motorcycle filter for Ducati and Harley. It has all the right stuff ( By-pass valve @ 9lbs pressure ) and it is 1/2" shorter ( 2 1/2 height ) than the Fram, which is great for where it gets located and also easier on the oil pump. It is chromed, but you can't see it where it is. The filter is as high as I could push it up and is completely protected behind the engine : nothing sticks out !
Finished late so I started the bike this morning. Oil wasn't coming out back into the frame after 10 seconds, got worried and shut it down. Looked around to see where I might have screwed up, nothing I could see so I started again. Within 3 seconds oil started coming out and after 2 more, it was a steady flow. At idle, maybe a bit less than before without the filter, but after that it seems just as good. So it takes a few good seconds to pressurize the system and fill up the hoses ( I had prefilled the filter of course ). As some have said, it would be easier to do it without the rear wheel. I left the wheel in place but I used a table lift. With the rear wheel and the bike on the ground, it would be very very difficult to install the filter housing & hoses.