It is your lucky day Bob, I've screwed up a knee and am home
evaluating pain medications!

F2000: 0 .62, Ferrari Formula One, 2003 David Bull.

F2004:  >0.68

...Normally expressed as lbs/hp in the US:  1.61, <1.47.

Ironically, recent F1's are going to yield the only reliable figures
(we know they ballast the cars up to the FIA minimum) as published
Ferrari road car weight figures are notoriously unreliable; it seems
there are at least three accepted industry and/or journalistic
"standards" for weighing an empty car, and they don't at all seem to
be reliably applied.  The initial figures supplied by Ferrari often
seem to be "bone dry", which, when coupled with large coolant, fuel,
and oil capacities, frequently yields deceptively low weight numbers
as compared to reported "as tested" weights, which then often include
additional unknown and unquantified test apparatus values.

A similar situation existed in published horsepower figures - brake,
gross, SAE, DIN - which seems to have resolved only with the advent of
worldwide emissions compliance.

Per arguendo (lb/hp):

250 GT Swb - 8.82

275 GTB/4 - 7.72 (has to be a bone-dry weight value)

365 GTB/4 - 9.71^, 10.03^^

365 GTB/4 Spider - 10.29, "with full tank"

512 BBi - 10.37, "with full tank"

308 GTB - 11.41, 1979 "with full tank" (Iirc, the 1979's had
completely fictitious horsepower claims.)

355 Spider - 8.77, 8.91'

288 - 7.26, 6.40*

F40 - 5.78, 5.07*

F50 - 5.21, 5.29*

550 - 7.68**, 550' - 8.17

575 - 7.41**, ^^, 8.04'

360 CS - 7.42'

Enzo - 4.63*, 4.97''

Ferrari, 1995 Konemann  
* Evo
** FORZA
' C & D
'' R & T
^Classic & Sports Car 2000, ^^2004

FORZA routinely reports both lower weight and higher power numbers
(direct from Ferrari no doubt, and probably Euro figures)  than other
publications:  If they actually do any independent objective testing
at all I'd be staggered.

Euro versions no longer have any emissions advantage (the 49-state
F-40 initially had more power than the Euro versions) but do still
enjoy a weight advantage due to US crash and safety requirements.