No strange "cackling" noises as if exh. manifold is cracked or smoke from tail pipes. I do run a 600 Holley Double Pumper (float level is fine and I'm not dumping gas into the vent bowl), Eddy RPM Int. & big cam (515/525). I've probably had the odor for longer than 5 yrs maybe close to 8 to 10. The original hood/cowl seal was pretty flat and flimsy compared to the new one I intalled. Over the years I've had a couple of friends that know how to turn a wrench and they all comment had strong she runs. I probably can use some headers to let her breath better with all the top end work thats been done. Yesterday was a perfect day to test the new seal...temps. were 90 deg. & humid. Typically after a good 30 mile cruise I would have to wash my face and change my shirt to get rid of the odor and my throat would be dry....None of those issues yesterday.