I just bought a used set of 416 heads off ebay, i am going to be installing new valve springs and seals. I have never worked on a head before so this will be a learning experience for me. I was told that i will have to reseat the valves, and that i will have to have a valve grinding compound. Does anyone know the correct way to do this and the full procedure? Or if it even needs to be done? I tried a search and didnt have any luck.

 

What has been described to you is called "Lapping in" your valves. Is it necessary? Well, take you head, put it on a stand of some description, and fill the chanber with water. See how fast it leaks out. Take a while? Do your springs and forget it. Gone a a couple minutes or less? Time for a valve job.

Since you have the heads off, and they are used, having a valve job done *just to be sure* is an excellent idea. Having them cleaned, etc. doesnt hurt either. All depends on how *used* they are.