Mark,
the 351W & 351C both share the same bell housing & motor mount bolt patterns. Besides the parts you mentioned, the coolant outlet plumbing is also different. Jerry at PI will have details regarding such a swap for you.
I'm sure you'll explore several engine options before you decide which way is the right way for you. It sounds like you want more than a rebuild of the 351C, you're looking for more bhp too? Can't say I blame you, it's in our blood, right? Can you say "gear head"? LOL
I will add this teaser for now. After 34 years, I am still stoked about the 351C. Its the cylinder heads that make this motor. Although many folks, including myself, lust after the alloy heads available for the Cleveland, the good ol' cast iron 4V Cleveland head will support over 500 bhp in a "streetable" state of tune. In other words, you do not "need" to shop for better cylinder heads with a 351C, with a Windsor, this is a must.
Mike Menolascino of Chicago has made 758 bhp at 7300 rpm with a 422 cubic inch Clevor, running cast iron 4V Cleveland heads with port stuffers. The oem 4V heads flow 275 to 295 cfm at 0.600" intake vlave lift, unported. Ported with stuffers, the 4V heads reportedly flow 375 cfm at 0.700" intake valve lift.
You have to buy a full race head for a Windsor to get that kind of performance. In fact, what are the best heads you can buy for a Windsor? That's right, canted valve Cleveland style heads!
The point I'm trying to make, your Pantera's 351C has a damn good set of heads on it. The Windsor's advantages are a greater ultimate displacement via stroking and more aftermarket parts are available at a somewhat lower price.
I'd like to make you aware also that the last few years have seen several new performance products developed for the 351C. The only performance product for the Cleveland that's missing is a good aftermarket engine block. An alloy block for the Cleveland is under testing in Australia, produced by SJ Performance, it's price landed in the US will be $5K! One can only hope that Dart will have pity on us Cleveland owners and make us a good iron block!
I gave DeTom a formula recently: hydraulic roller cam, Blue Thunder intake, 750 Holley, modern ignition & free flowing exhaust. Now add a stroker crank to that. That's about $6K in parts. With intelligent assembly, this engine will conservatively produce 500 bhp with a powerband of 2500 to 6500 rpm. Exchange the Blue Thunder intake for a Parker Funnelweb (or a Holley strip dominator), your peak bhp should jump to 540 bhp. The Panteras that raced at LeMans in 1972 made less bhp.
Your friend on the PIBB, George