Not selling or bashing anyone's product, just giving you alternative thoughts.
You might want to check with Dick Spadaro (he's on here). He has them also. One nice thing he does is use 1/2" lugs rather than the 5/8" that Speedway and the rest of the roundy round sources have. Small issue, but most of us have a store of 1/2" already. Another thing to check is clearance on the back. These are flat, so if your discs or drums won't work with flat because of casting lumps or whatever that's an issue. Also the lugs are usually large button head fasteners that protude on the back and can interfere with some drums or calipers, depending on configuration. Not sure if 5 on 5 is commonly available, might double check that, though drilling them for that isn't that tough for someone with the skill. Lastly, these are a common item for the roundy round guys and are often available on the usual known auction and resale sites. The concern with used though is racers aren't always kind to their parts (how's that for understatement?), so cracked or bent pieces may be why they're for sale, so personal inspection would be wise.
They do push the wheel/tire combo further out by the thickness of the plate, about 3/4" if I remember correctly, not as much of a problem on a fenderless car, but something else to consider.
