[Mgs] setting valves after head machining / 1500 MGA

[thgun at comporium.net]

I have talked to a few people about this and I am still not clear as to how to go about fixing my problem. I purchased a redone head. Now a few of the valves are too tight to adjust. Can I use shims all the way across to raise the rocker assembly? If so where can I get them? Any other tips.
Thanks for the help,
Tom Gunderson, 1957 MGA 1500 rst