From the FWIW dept:
The camshaft taper pin is available from McMaster-Carr.
P/N 98390A344 - Plain steel taper pin, #6 x 1-3/4" long.
0.341" Large end diameter, .305" small end.
Packs of 25 $11.58
I just got mine yesterday. They fit great, but 1-3/4" is maybe a little log and 1-1/2" might be better.
ALSO handy item from McMaster:
P/N 3088A433 Steel shim. 0.031" Thickness = 5/8" ID, 1" OD. Packs of 10 - $4.62
These are nice shims for the rockers, to space them away from the rocker block if necessary. (to center the rocker pads over the valve stems)
They fit over the rocker shaft nicely and are available in many thicknesses. I used 3 of these (.031") shims to move my intake rocker out a bit and improve it's alignment.