Now the second question is if the stock was bedded for an Impact Precision 737 and I want to put a factory Remm 700 SA in it will there be a need to alter or modify the stock?
Any time you place a different action into a previously bedded stock it is a good idea to re-bed. At the very least you can skim bed, but if it were mine I'd rough up and remove some of the previous bedding first.