[Prowbar]

Finally had time to continue the 478 build. I've completed the heads which have new valve guides on the exhaust side to accept the Cummins valves. Intakes were still fine regarding wear in the guides. Both exhaust and intake valves now have positive valve stem seals and were recut with a 3-angle valve job, with the intake having a 60 and 45-degree lead-in, followed by the 30-degree seat.
The exhaust has a 60-degree lead, 45-degree seat, and 30-degree exit cut. I used the specs in the book for the proper seat width.

I've ground off the "lip" from the Cummins valve to aid in airflow. I used the valve grinder to do this. See picture.

Finally, the heads could be assembled with freshened-up components. Then continuing the install of the cylinder heads on the block, followed by the valve train. I've set the cold lash to spec.

Before installing the assembled heads on the block I tested all the valves for leakage by spraying brake cleaner in the ports and checking for leaks. No leaks at all, so good to go. When cutting the seats, I coated them with a marker and turned the valve with a lapping stick to confirm the mating of the valve on the seat.

When installing the valve springs I noticed how little seat pressure the valve springs actually have. I might upgrade to stiffer springs later, but these will make for good break-in springs.

I will be painting the engine completely, but without the intake manifold so there will be good paint coverage on the valley cover and cylinder heads.
The intake manifold will be painted separately. The timing cover, water crossover, and oil pan will be borrowed from the 305.

In the picture, the intake manifold is not yet installed; just for mock-up.