And in addition to the above the 351W is around 50lbs heavier. A fair chunk of weight.
Depending where in the world you are buying a 347ci kit would be a better option and allow you to retain most of what you already have. Designed for putting in a 302 I can't see any reason it won't go in a 289. The 289 is supposed to have bores that don't extend down into the crankcase as far as a 302, but with the 5.4" rod kit that still places the piston .110" higher in the bore at BDC anyway.
The kit's reasnoably priced if you're in the states, but costly outside.
The Cleveland shares ALL the critical dims with the later Windsors (mounts & B/housing), being Windsor derived. It has a 9.2" deck height and a cast extension on the front.
Hope this helps, John.
"It's not always a case of learning more, but often of forgetting less"