Roush 427IR Idle issues

[169mph]

I have Backdraft with a 427IR with 3K miles. I normally pull her out of the garage and let her warm up for about five minutes before going for a drive. She usually idles around 1150 rpms. Here lately the RPMs will drop to around 800 and almost stalls before the engine RMPs jump backup to 1150. This will go on for a few minutes before the engine eventually stalls. Most of the time this happens after the car has been idling for a few minutes. Any thoughts? I plan to change the fuel filter and check for any obvious vacuum leaks around the intake. Before this happen I planned to change the fuel pump because the power and ground wires have come loose in the past leaving me stranded (bad connectors). I appreciate any help.