Power Issues after Tons of Work!! Help Please

Hello All,
Here is some history; I have a 1993 Mustang LX Convertible 5.0
Work done:
---Brand New Rebuild---
Stock 5.0L Block
Bored .030 over
Ported & Polished AFR 165/202 Heads
1.6 Roller Rockers
Forged Pistons
Forged Rods
(X Cam I believe - can find out for sure if needed)
Ported upper and lower GT-40 intake (as ported as they get)
30 lb Injectors
BBK 76mm Mass Air Meter
Hardened Transmission
ShiftKit

The issue is I feel like the car has virtually no power, plus it get a little hot, when running for a while. I know this isnt alot of info to go off of, however I am hoping someone can help. I have had it to mechanics and they have been worthless. I was told a new Mass Air Meter maybe needed, plus I know my intake is only "supported" to 400 hp, however I dont feel I am anywhere near that. I have been in 350 hp mustangs like my old Saleen and this car is a DOG. I think my wifes Prius could beat this thing.

Thanks for the help

1994 Cobra
2001 Saleen Speedster Conv.
1993 LX 5.0 Conv.