mlauk said:Make sure you get the H.O. engine with the 48RE automatic. The 47RE transmission could not handle as much torque and was only available with the S.O. engine. You can identify the engine HP by looking at the sticker on the engine.
2003 S.O. Federal Emissions: 250HP/460lb.ft. Available with NV4500 or 47RE
2003 S.O. Calif. Emissions: 235HP/460lb.ft. Available with NV4500 or 47RE
2003 H.O. Federal Emissions: 305HP/555lb.ft. Only available with NV5600
2003.5 The 47RE was replaced by the 48RE automatic transmission and available with the H.O.
Now.. I am not the sharpest knife in the drawer, but I looked at the sticker on the engine of my '03 and could not match a single number on there. Nothing close... better be more specific....Ok the not close was not true I suppose because I am guessing by the serial code it's the 5600