I may have a connection for some parts through a member of the local Mustang club I met at my first meeting. I am not in the market for much but thought that a good head would be a nice aquisition for future.

He said he maybe has SVO, TC and possibly Merkur heads. What would be the subtle or other differences for performance etc. between them if any between years and models?

What would be things to look at to identify each (cast numbers etc.) and what do I look at for potential issues (cracking or other)?

Thanks for your help.