I'm just curious. Have a set of Agistino ported iron heads on My Impala that have 2.05/1.60 valves in them. Not much room between the valves. I've been told that is the largest valves they have seen on stock castings. Is this true? or can you go 2.08? I don't see how. Does it make a differece whether they are cast iron or aluminum heads?
HVY SS

 

2.05 is the biggest I have heard of.

 

I saw a set from CFM that had 2.08, so I guess its possible.