Drill hole in front spring hanger

Ok so got my new leaf springs XHD+1 and I need to drill a biger hole for the bolt that goes through the front spring hanger.Does anyone know what size bit to get the right hole.Thanksssssssssss.

Did you buy the XHD's from mancini?

If so, they recommended I buy their hanger:

Mancini A-Body Dual Location #MREAR0077.……………………….……...$67.95

This hanger has the correct size holes for what you're trying to do.