There are two ways commonly used to stroke a 351W. The old way was to use a 400 Cleveland crank machined to fit the Windsor block. Special pistons are needed and the block must be clearanced to allow the rods to miss the pan rail. Displacements run as high as 430 cubic inches. Stick with around 408 CI for an engine that will last a while. The piston skirt gets really short on the bigger versions which gives poor ring sealing and short engine life.
There are now available new cast iron and forged cranks for this mod from several aftermarket companies because 400 Cleveland cranks are getting hard to find. This is not a job for the corner machine shop, I recommend you buy a complete short block from one of the many companies that specialize in stroker kits to save money, time and heartache. Coast High Performance in California has these short block assemblies for around $2500.00. It's a good deal and you won't regret dealing with them. Ford Racing Performance parts has one available too for a little more.
Royce you forgot about offset grinding the stock crank. I had one one time, the 2.3 rod journal was offset ground to the stock big journal sbc 2.1. Ended up 377 ci. Dont discount the durability or it either, I ran mine in a late model dirt car at 7-7200 and it never gave a moments trouble and that was at 13.8 compression.
Its not worth it to do it today though as you mention the new cranks you can buy outright. Right now the 393 is the hot ticket, uses stock sized 351 rods and 302 pistons with out really any clearencing so really if a man is skilled enough to do a stock rebuild he should be able to do the 393 himself although I do agree on buying the shortblock (or long block) if someone is not that mechanicaly inclined. mm