Being a curious person, I looked up the specs on that Melling part number, and it does not appear to a turbo application?
After 30 years, many aftermarket suppliers label many parts as a fit-all "generic" replacement, not really an exact replacement.
Most turbo Buick engines from the beginning years ago used the 206/206 grind cam as a stock replacement, and at least you would be assured that you receive a cam for a turbo application.
This is still the most common cam we use for stock rebuilds.