Problem getting 429 cobra running

[ivantodd]

I have a 429 that's just been rebuilt from the ground up. It run's great while in park but as soon as we put power to it , it dies.. Looked for vacum leak and checked timing . Anyone have any idea's?

[TButtrick]

What carb(s)?

[rustyBob]

what do you mean by "put power to it"

does it run in park when you rev it up ????
does it run when you put it in gear then die when you
put a load on it ????
do you have electronic ignition ????
electric fuel pump????