The camshaft is the single most part that determines how the engine is going to run and where the power band is, everything thing else either complements it or detracts from it. Stroking and increasing cubes makes more torque, it has nothing to do with whether an engine lopes or not. Many of these crate engines are cammed more than stock, so you need to be aware, and select what you want accordingly, if it is a daily driver no hot rodding, then go with a stock cam you will have the most engine vacuum for power brakes if you have them or want them, the smoothest idle and the best gas mileage, if you want a little more power then go with some more lift about .5" and keep the duration and overlap down to near stock or a little more, if you want more power then you have to have more duration and overlap to move the power band up the rpm scale, this is where the loping idle and poor low speed operation come in. So my advice is your 347 stroker is probably cammed to produce more hp as such it will never be smooth, but it will be driveable, and if you like the acceleration, you will get used to it. And as the others have stated, you may need a tune-up or have the carburetor checked and or adjusted to get it the smoothest it can be. My 2 cts. Good Luck.