None at all. 260 kW (350 net hp at the flywheel) is the limit for the rod bolts on a regular un prepped basis. 1983-1985 AIT Turbos used 9 psi boost, and gave 270 hp net (200KW). Stock 4.1 Pistons are okay as long as the rev range is not raised above 4500 rpm for a post 1985 engine. Short stroke Falcon 3.3's reved to 5500 rpm, so that fixes the maximum design piston speed to 4800 rpm for a 4.1 x-flow.
Main issue is compression ratio. EFI engines ran 8.8:1 right through every year, but carb engines varied from 9.35 until Jan 1986 to 8.7:1 for post 1986. After 1986, the trough in the pistons for X-flows was increased to lower compression.
Mike Vine and AIT and Garret Air Research Australia Prty had good results with 7:1 compression via machining head or via one 1.5 mm spacer and two head gaskets. So C/r is reduced via 59 thou of steel and then an extra stock 41 thou of stock MonoTorque head gasket for a deck drop of 100 thou. Similar to the stock US 250 arrangment.