Scalpel

iTrader: (4)

I get a stumble at PT only. If I increase the throttle to about 3/4 it'll go away and run fine but if I have the throttle at a low PT I can feel and hear it stumble. My plugs are new, and the wires have all been reseated. It happens mostly in 1-3 gear.

Cal

iTrader: (1)

Maybe the engine needs more fuel. I'm sure you have tuning for that 427. Try jacking up the VE a little for the rpm range you're having problems with.

Scalpel

iTrader: (4)

Thanks for the tip! Would it have started out of the blue for no reason, though?

Cal

iTrader: (1)

No if it just started outa the blue, you have some other problem, unless the weather just changed. Plug wires have a double click when they go on; if you only get a single click they aren't on good enough. Maybe change out your fuel filter and air filter as well. You may need injector cleaner or new injectors. If all else fails, log everything you can think of with EFILive then study the files for anything outa whack.