Aftermarket alternator mounting bracket for 1970 340

Not sure if it's been mentioned, but if you enlarge the 2 bolt holes that goes to water pump it will bolt on?
The engine is a 70 model with original cast iron "O" heads and aluminum water pump. Ordered bracket accordingly to fit 70 or later with aluminum water pump. As stated earlier, brackets came from Mancini and 521. Just ordered bracket set from Bouchillon. Will see what they can do. Next will modify bad bracket as suggested. Cut to match, beat to fit and paint to hide.............