I'm not familiar with a clutch screw kit either, but maybe I'm just behind the times. But ..... I do frown upon most of these chopper site's offerings. Especially after (trying to) use some of their motor stands and wiring harnesses. They're absolute junk and cost big bucks in the process. But that didn't answer your question now did it.
OK, here's the best info I can offer at the moment - the Athena kit is very good, probably just fine for most. The base gasket included in the latest ones is chemically treated and needs no additional sealer. The head gasket is thicker than stock, always has been. Some say this will reduce your power output. It probably will, but is it enough to notice? For most of us, probably not. This kit includes the valve guide seals but not the valve cover o-rings.
The other gasket set available is the Vesrah one. 650Central sells it. That head gasket is the same as the original so no power loss? But, no valve guide seals in the kit.... but there are the valve cover o-rings.
So, I guess it's a toss-up. Personally, I've used several of the Athena kits with no problems. But ..... with this head gasket thickness thing, and the availability of premium Viton valve guide seal from eBay, my next overhaul will use those and the Vesrah kit.
