[DeTomaso] Valve Spring Shims

[John Taphorn]

I am freshening up a set of heads recently acquired that had been 
sitting for several years.  However, previous owner thought them to be 
bolt on ready.  Upon dis-assembly, found there to be no hardened spacers 
under the valve springs.  Many years ago, I assembled a Cleveland head 
w/o shims and the rotating valve springs cut grooves in the cast iron 
seats.  I have always cut the seats deep enough for a shim since that 
experience.  However, perhaps the cutting issue was my failure to debur 
the springs' leading edge.

What is the consensus among engine builders - Shims or no shims, 
assuming proper spring height w/o them?

I'll probably shim these anyway as spring height is inconsistent, yet 
around 1.90""

Thanks
JT