It can be done because me and my dad did it on his van....yep a ford van....but we used a drill press...and made a jig that made sure all the intake holes were the same....besides hot rodders have been doing it for years and so have race car people...but jus make sure u line things up and make it even for all holes....besure nothing is left on intake to fall in motor....maybe ask someone at a local race shop if they can give u some insight or pointers on how to do it the best way possible
