I had a 351-W in my 1978 Zephyr Z-7 (Fox 3 chassis). Its doable, and you need a handful of extra parts, over just rebuilding your 302. My current combo is an S-trim on a TFS TW 302.
Granted there is no replacement for displacement. You just gott figure in the oilpan, headers, intake and misc minor things.
www.alternativeauto.com has a decent article about this.