can anyone give me some info on these heads?
are they able to be used on the type 4 engine and if so are there any advantages/disadvantages associated with these, and whats the valve sizes?
if they are a good thing i can pick up a pair quite cheaply!

I dont think you would want to use them on a Type 4 engine as the Vanagon heads are Water cooled and the type 4 are air cooled.
Unless you want to install a special head radiatorfor cooling. I dont think theres any advantage at all.

whats a vanagon?

Now, now Chris....Don't be like that!...

The Wasserleaker isn't bad engine.....

But a 240hp/309flbs Subi six is better!

I know a guy who tried these heads on racing baja years ago....Didn't get any real advantage with'em...Just more headaches with the cooling stuff...more weight, more things to go wrong, etc!

do you mean air cooled or water cooled? the very first caravelles (vanagon in the USA AFAIK) was air cooled.