I posted this in Carbs but haven't gotten a response and I need to figure this out....

So I bought this 1986 Camaro tha is supposed to be completely stock except for the rear gears which I believe because of the appearance of the car and underhood and such, it has the 305 motor and 700r tranny ..... anyways...

The problem is when the car is sitting at a stop and also when it goes to open the 4 barrel, there is a pause. Not a slight hesitation but a literal second or two stall before anything happens. I was wondering if this was a carb problem, if you ease into it from a stop it will go fine but seem a little slugish and at WOT the pause kills me. Any help on this would be great, I'm not sure where to start honestly.

One more thing, sometimes when I put it in neutral or park the RPMS go up to around 1500 when at normal idle it only hits 700 but if you tap the gas, most of the time the rpms drop back down to normal. What would cause this to happen?