The 880 blocks had everything for a roller cam, but often had a flat tappet cam installed at the factory. The 880 block I have in WCJr was flat tappet. I bolted the Vortec parts right in place and run a Lunati cam.Does it look like this block was machined for a roller cam & lifters? I see four holes that have threads for the lifter spider and flat surfaces for the dog bones...puzzling.