Greg, the front of the 351C intakes have to be cut away primarily in order to clear the water jacket passage in the intake adapter. Not a whole lot has to be cut off in order to do that, but if you cut away most of the bottom of the intake it exposes the machined valley cover plate, which looks better than just leaving most of the cast intake in place. This is especially true when running a tunnel ram; they look really good with the center cut out.
The Edelbrock 2863 is not an intake for a 351 Windsor, it is for a Yates style Cleveland intake. It will not fit the standard 13001 intake adapter, you have to use the 13006 adapter and also cut about 0.350" off the flange of the 2863 intake to make it work. The 2863 intake is capable of a lot of power but is best reserved for a rather high horsepower application. The Performer RPM that Marc shows in his post sounds like it would be a better fit in your application. I have not tried a Weiand Stealth intake on the intake adapters, but if it has an exhaust crossover passage underneath the manifold, like a Holley Strip Dominator does, then that may have to be milled off on the bottom in order to bolt on to the intake adapter. Wouldn't be a big deal to do that, especially since you have to cut the 351 manifold to fit the intake adapter anyway.
Glad you like the timing cover - Jay