It depends on the weather. If it's 260 with SAE correction, it could be actually putting down 280+ if it's cold outside. I have trapped 105 with only 280rwhp (SAE).

A published comparison ...
 

Apr 2006 issue of 5.0 Mustang
Article: Zoom at the top

Base line run was made with the following mods on a 5spd foxbody:

Exhaust: FRPP Shorties | High-Flow Catted H-pipe
Air Induction: 75mm Pro-M MAF | Mac CAI

220 HP | 277 TQ
___________________

And here's the TFS Street Kit with the following mods:

Heads: Twisted Wedge
Cam: TFS Stage I
Intake: TFS Street
Rockers: 1.6 TFS Rollers
TB: 70mm Accufab Throttle Body
MAF: P-MAS 80mm MAF
CAI: AFM 4" Powerpipe
Exhaust: FRPP Shorties | Catted H-pipe

292 HP | 316 TQ

In this example the foxbody netted 69 peak hp from the TFS kit with additional changes.

Crzypny's comparison ...
 

94 GT baseline with the following mods:

B303 Cam
MDS Coil
FMS Shorty Headers
O/R H-pipe
Flowmaster 1 chambers

213 HP | 277 TQ
_________________

TFS kit minus cam with following mods

Heads: Twisted Wedge
Cam: B303 Cam
Intake: TFS Street
Rockers: 1.6 TFS Rollers
TB: 75mm
MAF: 90mm
CAI: AFM 4" Powerpipe
Ignition: MSD 6A | MSD Coil
Exhaust: FRPP Shorties | Prochamber | Mac Catback
EEC: SCT Chip
Gears: 3.73

268 HP | 305 TQ

That's a net gain of 55 peak HP without the benefit of a cam upgrade.

When you put it in perspective like that...sounds about right. I think a cam change is next on the list. Because it's about the same cost as a set of good rockers, which you already have on there.

rockers would be a whole lot easier to change vs a cam swap. Besides, while the 'b' cam is a old design it is still a good cam. I proved that with my first combo on the cobra