I have a 1997 mustang it used to be a v6 but i swapped it the the 5.0 v8 and ran the new wiring harness and everything
I tore the motor down to the block and rebuilt the entire motor i kept everything stock except i did the following upgrades
E303 cam
gt40 heads
cobra intake
70 mm throttle body
new plug wires
Underdrive pulley kit
373 gears in the rear
shorty headers
True dual exhaust

NOW WHAT I NEED HELP WITH (ITS DRIVING ME CRAZY)

When i first start it up until the motor gets hot when i give it gas it like backfires up through the intake and makes popping noises and second its lacking a lot of power even when its warmed up and been driving for a while i mean i can only chirp second i would think with those upgrades i would be able to spin first second chirp 3rd something like that

Let me know what you think or what could be wrong cause im going crazy trying t0 figure out what it is i think with those upgrades spinning tires wouldnt be a problem but im lucky if when i step on it in first if the tires chirp or spin it just goes its like my v6 was

 

For the backfiring, check your timing with the spout connector removed, should fix it up and give you some more power.. As far as the chirping gears thing, what tires are you running? You shouldnt be too concerned about that, I have basically all the stuff you have listed there, and I dont chirp 3rd with 315/35R17s and 3200lbs

 

ok ill work on adjusting my timing and see how it goes