When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
S1 has a full width Rad where as the S2 Rad is only about 3/4 of the size with the IC beside it, a S2 FMIC makes use of the space left by removing the original IC which you wont have as your Rad will be filling that space.
Not sure how that will affect your fitting but something to bear i mind mate.