Unequal Exhaust

The exhaust pressure on the right side of my 83 Mondial QV is noticeably stronger than on the left side. Does anyone know for sure how the stock muffler routes the exhaust? I believe that it is not a true crossflow muffler. Instead, the right side input ends up on the right outlets. The left side input ends up on the left outlets. Both my Cats are empty and there are no leaks. I removed the muffler and emptied out pieces of the Catalyst Matrix. Then vacuumed it out; then flushed it out with water hose. But still have unequal exhaust pressure. There has to be some blockage somewhere?

 

Thanks for the replies! Yes, I had heard from some service personnel that this was supposed to be a normal condition; but got the impression that they just didn't want to bother checking out my car - I do most of the wrenching myself, anyways. The weaker exhaust side seems to be from the front bank of cylinders, which does have the longer length pipe than the rear bank. I checked the pressures at each of my empty cats by removing the air injection pipes and fitting brass adapters for a gauge hook-up. The back pressures are not quite the same. Even without the gauge, I could feel the difference in the stength of the pulsations with my thumb. The front bank is slightly higher than the rear bank, i.e. front bank cylinder flow restricted as compared to rear bank. This can only mean that either the stock muffler does not flow equally or perhaps combines the flows in some way.