Bogging out after a couple of hours driving

I have a 1990 Cadillac Brougham the car runs good, starts up find does not shake at idle it does smoke quite a bit and I know it's burning oil but overall it drives pretty normal
But after driving it for a couple of hours around town it starts feeling like it's bogging out at take offs once I get to a higher speed it goes away but as soon as I stopped at a stoplight You can feel a slight jerk it's not that bad you can barely feel it when you take off. Could it be something to do with the carburetor I know it can use a rebuilt my friend told me that it could be the EGR valve is plugging due to the fact that the car smokes quite a bit so my question is could this be a carburetor problem or is it something else. The bad thing about these carburetors is that nobody in my town knows how to work on them are rebuild them anymore if somebody can please give me some advice it would be greatly appreciated thanks