Jets are not normally replaced as they do not wear out. You change jets with altitude changes or engine changes that requires different sized jets.
40 years ago, Carter made kits that included jets, but that required a different kit for each vehicle. Over the years companies needed to consolidate carburetor kits in order to save money and jets were the 1st to go.
At any rate the W-1 jets are not produced these days.
To reduce jet size for altitude, solder the jet shut, then drill .002 smaller than the starting size.
Not sure if you have the correct jets? Jet Sizes