68 Cuda 318 valves, 904, driveshaft

Were the valves installed in heads? Im curiouse because my factory manual shows 2 different valve face angles for 69 and 84. Im using 302 heads from mid 80's. Ex and Int for 84 is 45* But for 69 318 Exh is 43* and Intake is 45*.
So exhaust is slightly different.
Make/part #?
Thanks
Steve