will the rb 2.3 is not a bad motor one company in in japan made over 1000 of them should rev fine with good rod bolts these motors need custom pistons to suit of 81 or 82 mm tomei make the pistons for the 2.4 they are 30000 yen each or $440 each so nearly 2500 for just pistons at least 1 k for the machine work 1k for gasket etc then 1k for assembly you see where its heading then if your going to do all this work you want a big MOF turbo with external gate 3-5k then you need injecotrs afm the the rb20 box wont be strong enough so you need an rb 25 box 2k + with clutch its not worth it unles syou going for an all out track car to take a record with the 2.4 kit I have seen 700 hp + made with t88 turbos.
and the stock rb 20 will handel 250 rwkw so why change
meggala