Drove the 260 to work and was puzzled that after all the effort to change the plugs ( thread in V8 forum) and put on new coil packs, she wasn't really running very well at all. Poor acceleration, nearly stalling pulling off at low revs in first gear. One sick puppy
Got home and had another look. Forgot to re-connect the MAF sensor!
Goes like a train now. Glad I didn't post to ask for advice