Head specs

[Richard Taylor <n196x@mindspring.com>]

Fellow FOTers,
I bought a junked TR-4A motor to rebuild incrementally whilst continuing to
drive my machine.  Step one is to rebuild the head. The head thickness is
3.328in. Has this head been shaved?  I plan to shave 90 thou off.  Is this
too aggressive?
The valve seat width apprears to be only 1/8".  Is a multi-bevel valve
grind possible?
Any other rumors, gossip or personal preferences with regard to rebuilding
a head is greatly appreciated.
Thanks for you help
Richard Taylor, HSR # 96