Who can figure this out?

I have an intermitten(sp?) problem with my car, mostly when its rainy or when im driving slowly such as in traffic. It idles great, but when i release the clutch and give it gas, the car sputters, loses power temporarily, then pops and takes off like a bat out of hell. This happens usually only happens up to about 3000 rpms, otherwise it will drive great when im in a hurry. I just took the engine apart and replaced a head gasket, and most of the others, so i know its not that. And it happens in every gear, but not all the time. Heres a copy of my mods list and maybe someone can come up with an answer for me, which would be amazing. Thanks everyone!:SNSign:

Eibach Road race springs 2.5” drop
KYB 4-way adjustable Struts/Shocks
Lower Control Arms
Boxed Reinforced Torque boxes
Weld in Sub-frame Connectors
3.55 gears
Rebuilt 302 w/40k miles (as of 87k)
GT40 Intake w/ 1” spacer
GT40 iron heads
Stud mount Lunati 1.60 Roller Rockers
Crane 2030 cam (270/270/.55-.544)
Crane Ignition Box
MSD coil
24lb. Injectors
FRPP 9mm Wires
65mm Throttle body
77mm Pro-M mass air meter
Pro-M intake pipe
k&n filter
Bosch Platinum Spark Plugs
Ford Motorsport valve covers
Underdrive Pulleys
255 in-tank fuel pump
Mac Long-Tube headers
Off-Road H Pipe
Flowmaster 2 chambers
3-Core Radiator
Black Magic Electric fan
Rebuilt T-5
McCloud clutch
Hurst short shifter
MGW Shifter handle
Pro-5.0 shift knob
Autometer Fuel Pressure Gauge
Autometer Oil Pressure Gauge
Autometer Water Temp. Gauge
Autometer Boost/Vacuum Gauge
Autometer 5” Tach w/shift light
Air/Fuel Gauge
Infinity 2.5” dash speakers
Eclipse 6.5” door speakers
MTX 5x7” rear speakers
Alpine CDA9855 Head Unit
Ultra-Clear Headlights
5% Limo Tint
Nitto 555 Drag Radials
Silver Pony wheels
Cervinis 2.5” Cowl Hood
Bright Red Paint
Black Interior
AC, PS, PW, PL, Air Bag