Daz,
There are plenty of twin & triple carb manifolds out there. Also, it is very easy to find a finned alloy rocker cover if you need (dozens of styles).
Internal stuff like "Weslite" pistons, cams, bearing caps, are all getting rare.
But if you want something SUPER rare, go for the special heads. A "Repco Crossflow" head, will (As Ken said) set you back about $10,000.
I have a friend who had a Waggot twin cam head, which was the 3rd one cast. It sold for $25,000.
He also has 3 Dunstan Rotary valve heads, one of which is NOS. These will pull about $20,000 - $25,000 if he ever sells (which I doubt). These items were extremley rare in their day, but 40 years on, Man, you get the picture.
Still, always keep your eye out, as you never know what you might find in that old shed!! Just ask Tony (Norman Supercharger article), he found one NOS on a shelf in a wreckers!!
Rob
