Idle Troubles

[Yankeelights]

OK, I'm stumped. I installed the ol' 406 as planned but I can't get the thing to idle correctly. I can start it up and while it isn't in gear the engine races; then loads up and shuts down. If I start it and immediately put it in gear it seams to idle fine. When I tromp down on the throttle, there is a slight hesitation then the ol' 406 lights up the tires and sends me down the road sideways. On the highway crusing at 60 mph, I can feel the engine hesitate a little before going uphill.

• Vacuum leak(s)? I hooked up no emissions; just the pcv, vacuum advance, brake booster and vacuum modulator line with all new line. Everything else is plugged.
• I converted to electric choke. Could the vacuum port built into the choke housing be causing me problems?
• What's an effective way to check for vacuum leaks around the manifold?

I'd like to rule a few things out before I look at the carb. Any insight is appreciated!

~ Dave