71 198 slant new head

There is no problem using your old valve train. Did you readjust the valves? Should be .010 on the intake, and .020 on the exhaust. Don't forget the valve sequence changes between cyl 3 and 4. As far as I know that bolt is not available, except as used from someone's private stock.
Yes I did cold adjustment & hot at 10 /20 hot .