I set mine up so that the inlet ramps (attached to the top cowl) were wider than the baffles. That way, the seals on the baffles just reach up and then bend inward as they hit the top cowl ramp.
When I originally built my baffles, I thought the sides of the baffles were supposed to "bound" the ramps on the top cowl. I had it backward. The ramp should be wider than the baffles.
Not sure if that's clear as mud or what, but here are some half-as s pictures:
http://www.rvproject.com/20040118.html
http://www.rvproject.com/20040205.html
Hope this helps. Best thing to do is go take a look under the cowl on an RV that you trust is reliable and FAST. Short of that, beg for some more photos on the web...