Rebuilding the bottom end is never a bad idea, especially when you're going to be taking it to some really high revs.

My mate Neil (rs20004x4 on rs2000-16v.com) has his RS2000 running 170bhp and about 149lb.ft torque at the moment. The limiting factor is that he's just running superchipped standard management on it. The only work that's been done to the engine is a K&N panel replacement filter (not cone!), standard engine internals, EGR removed (including grinding open the exhaust ports on the head), Mongoose exhaust with de-cat pipe and Optimax.

The graph was pulling all the way to the redline - if he had the bottom end rebuilt and some lairy cams installed as well as full mapping on aftermarket management (with appropriately specced injectors) I reckon you'll see over the 200bhp mark easily.

The 2.3 option would give you bags more torque - but it sounds like you want high revving antics instead

Cheers,

Andy