New 331 dyno #'s poor!! Help!!

[Blaster]

I recently ran my new 331 set up on the dyno the yesterday and was VERY dissappointed. My car made 270rwhp@5500 and 291tq@5400 I believe (forgot the sheet at work). My engine is basically the complete edelbrock performer package (except with RPM intake) stroked to 331 cubes with the heads and lower intake ported. To summarize:6037 ported edelbrock heads(1.60/1.90), e-303 cam, performer rpm intake with ported lower, 1 5/8 shorty headers, x-pipe with 40 series flowmasters and turndowns, 24lph injectors with 75mm matched mass air meter, 70mm trottle body, 190lph fuel pump, and underdrive pulleys. Anyhow we took off the mufflers and only gained 4hp, and tried taking off the airfilter (gained 2hp). I put it on the scope today and no cylinders were dead although the voltage was low. I tried my buddys blaster coil and it didn't make much diff. either. Whats wrong here??? I e-mailed one guy and was told my heads are too small, my headers suck, my trottle body and mass air are too small and my cam is too small. OK fine but my car without the stroker kit and head/lower manifold porting made 250rwhp and 270tq last year. It's just very hard to believe stroking the engine and porting the heads and lower intake would only net me 25 more rwhp. My dyno guy tunes many 5.0's and thinks output should be at least 300rwhp so were is my problem??? I don't have thousands of dollars more to put into the car. Could it be the cam? The stock igniton system?? What gives? The dark side is looking really tempting right now because a stockish LS-1 car makes about 300rwhp and my big expensive 331 can't even come within 25 ponies!!! Help me.