Help: 2001 Cobra Dying out after engine rebuild.

[332cobra]

hi!

yeah so far i've been tapping the gas as the rpm's dip down below that 700hp mark, but before the rebuild i never had to do that to keep it running. i was wondering if a tune up or a particular brand of spark plugs might help with idle.

this only happens while cruising in neutral. the rpm's fluctuate, which is odd to me. as if the rotation of the drivetrain is affecting the idle rpm's of the engine. is something catching?

i posted in this forum as the engine is a 4.6 liter 32 valve, hope i got it right. do the windsor guys have better feedback on this type of stuff? thanks for the help thus far.