Fill cap on a 1600 radiator

[<tputland@charter.net>]

I was thinking about putting a filler cap on the radiator for my 1600. I have 
seen pictures of this done using the same set up as the 2000 radiator and now a 
picture on the 311.org site of one on TOP of the radiator.... With a fill cap 
on TOP of the radiator what is clearance with the hood? (The 311.org write up 
says "The owner reports it clears the hood but barely") 

IF I have to use the 2000 set up, where can I get one?

Thanks 

Tim
Belleville, WI.
'70 SPL AND SRL
Still clueless but always learning