Both are correct, but as for which is better I am not sure. I have the bearing type, which I have not installed yet. From looking at where the grease comes into these kingpin assemblies, I have hard time imagining how the bearing is going to get greased effectively. I will grease them well before installation anyway. When I took the old kingpin assemblies apart on my truck I had a bearing-type on one side and the washer-type on the other side. The bearing type was frozen-up without any grease in it to be seen anywhere, but the washer type bearing still had grease between them and moved well. I purchased this truck 1.5 years ago and I have no idea how well these kingpin assemblies were maintained.

1954 GMC 1/2-ton Longbed
1971 Pontiac LeMans Sport