I tend to agree that the d'Amico & Tabucchi book is probably the best source -- if only because Fusi and Catalogue Raisonne books cover cars only to about 1982. The d'Amico & Tabucchi book is probably the only book that covers the whole V6 range. Then again, published performance data -- no matter whether stated in books and sales brochures -- need to be taken with a grain of salt, as the numbers may reflect certain legal requirements (e.g. taxation) and/or adjusted performance (e.g. to meet smog requirements) in certain jurisdictions.