Check out this page here:
http://www.warmoth.com/Guitar/Bodies/Options/BridgeRoutingOptions.aspx . Scroll down to those bridges and you'll notice when you click the brown box on the right to see the line drawing overlay that the string through body holes are in a different place killing the option for an over-rout for the American Standard. I think you can order a body from scratch with that bridge rout though. You may have to modify the pickguard slightly since the bridge sets further toward the neck a bit. Might not be able to remove much material from that slim strip. Perhaps consider having the existing bridge rout routed over for the narrow spaced Strat flat mount bridge, then buy replacement saddles that are like the American standard. That way you achieve the string spacing and heavy duty saddles of the American Standard bridge.
