94-98 and 99-03 difference?

whats the difference externally and internally, like engine and shit.

94-95
3.8 OHV @ 145hp
5.0 OHV @ 215hp
Cobras had 5.0 OHV @ 240hp
T5 transmissions
Smooth sexy bodylines, aka SN95 style
Return fuel system

96-98
3.8 OHV @ 150hp
4.6 SOHC @ 215 (225 in 98) hp
Cobras had a 4.6 DOHC @ 305hp
*S or D means single/dual, respectively*
The GT and Cobras had a T45 mated with 3.08 gears
SN95 body
Return fuel system

99-04
3.8 OHV @ 193 (188 for the 99 model year)
4.6 SOHC @ 260hp (Bullitts had 275hp)
Cobras with a 4.6 DOHC @ 320 (99 & 01)
Cobra R with a 5.4 DOHC @ 385 (00, closer to 410+ at the crank)
Cobras with a 4.6 DOHC @ 390 (03-04, closer to 420+ at the crank)
4.6 DOHC @ 305 (03-04 Mach 1s, closer to 330+ at the crank)

The 99-2000 GT had a T45, while the later 2001 to current GTs run a 3650. The Cobra in 99 had a T45 while the 01 had a 3650. The Bullitts and Mach 1s also have a 3650. The Cobra R and current Cobras run a T56, but with different gear settings.

All cars from 99 to current run a returnless fuel system.

All cars have the new style, called the "New Edge". Some people call it the second gen SN95.