When I was looking for a cam for my 360 powered, stick shift Diplomat I narrowed it down to either the XE268 or the XE262. I went with the 262 and yes it was noticeable over the stock cam. Your setup with 35's and 3.73 gears will be close to my setup with 27's and 2.94's. Other than valve springs you do not NEED the rest of the stuff mentioned. If you want to dial it in to a polished turd finish then yeah you need it.

As side from the supposed needed extras to put the 268 cam in, I'd go with the 262 if I was choosing, more grunt down low.

They say there are no such thing as a stupid question.
They say there is always the exception that proves the rule.
Don't be the exception.