Just to clear some of this up, the differences between the 2.8 and 2.9 are: Bore / pistons Compression ratio Cams Inlet manifold Exhaust manifolds Throttle body ECU . They share the same ECU per revision, just the software is changed. ie 258CH and 258CP is the same ECU, just the software is different. So when converting, you don't actually need to change the ECU. When comparing 2.8 to 2.9 be sure that you have a REAL 2.9 as these appear to be rare these days.