Why not talk to Webster racing or Hauser racing or even US Automotive !!
They all have containers shipped in from the states weekly or monthly. Maybe you could do a deal to purchase the heads from them if they ship them in??
Just a thought
Perry Stephenson
MGB GT + Rover V8
9.62 @ 137.37mph
Now looking for 8 seconds with a SBC engine
http://www.youtube.com/watch?v=nVscbPHgue0&list=UUqIlXfSAoiZ--GyG4tfRrjw
In my recent travels, I can pass on a few nuggets of data. A set of Buick 300 heads weighs in around 41 lbs. Not much different than the Rover heads. ONE 65-67 cast iron Buick 300-340 head weighs 45 lbs. Of course, it's intake and exhaust ports are twice as large as the Rover's. So, to use the iron heads, you'll effectively add nearly 50 lbs to your chassis. They also have the same chamber volume as the alloy Buick 300 heads.