On the V8 whether it's a 3.5, 4.0 or 4.6 there are definately 4 allen screws, they are 1/4UNC-NOT metric (Like the rest of the crossbolted)-need a 3/16 A/F allen key- on each rocker cover. Two short & two long. They are usually hidden below a loom on the inside and are not opposite the ones you can see on the outer edge-the centres are wider. I know this for sure as the later rubber gasket has four steel spacer inserts to prevent the gasket being squashed too much furthermore I replaced my rocker cover screws with stainless allen screws from work and I took a few extra for spares. I use a "T" type allen wrench to remove/replace them.