wellllllll---Buick? anyway, are all the pistons new? If so I would suggest maybe another block as you will have to have 2 different sizes of holes, and/or-----if new 040, you would have all 8 holes same size-------

However, if you are thinking about going bigger on those 3 holes-have it done by somebody with a Sunnen CK10 hone and go til holes are clean, check sizes, check availability for pistons same compression, cast or forged same as you have , balance, etc and finish to the size necessary--------