Some early 351-Windsor blocks turn out to have the same thin cylinder walls as was infamous for Clevelands, as the Ford Casting Plant #1 in Cleveland switched its casting technique to the new upside-down 'thin-wall' method. So using a W block is not an automatic free pass in overboring. I've also heard of wall problems with early 302 blocks, for the same reason.
On a pair of 0.030"-over blocks- one later blew during a SS race, and another that cracked after a backfire (cold engine) on the starting line, (coolant running out the right tailpipe), I found pieces of off-center cylinder wall only 0.070" thick. Chevy guys get nervous if their cylinder walls drop below 0.200"- which NO factory Cleveland ever had. I suggest sonic testing ANY '70-74 V-8 Ford blocks for wall thickness checks, if you intend to bore oversize. YMMV....