if you are going to go out and buy all new the windor swap wont be cheap. but if you know what you are doing and look around you can do it cheap. if you are comparing a no expense spared dart 8.2 deck build to a cheap overbore only windsor build, you are comparing two different animals. the 8.2 will be faster, but, ive gotten 10:1 358" windsor shortblocks with ported stock heads into the high 10s naturally aspirated with a flat tappet cam. so it can be done. if you are reusing the stock windsor crank, rods and block it can be a cheap build that will hold 700hp. even if you are going to buy a cast 408 rotating assembly its still not that expensive and can take you into the low 10s on motor if done right. they are no 4 bolt block but they will live a lot longer than even an early stock 302 or mexican block.