Deceleration popping at the exhaust on 1972 240z
 

Just replaced my former stock 2" exhaust system with Dynamax muffler with an MSA Premium exhaust for stock manifold system:

Motorsport! MSA Premium Exhaust System, 70-72, 74 240Z-260Z (For Stock Manifold) - The Z Store! Nissan-Datsun 240Z 260Z 280Z 280ZX 300ZX ( Z31 Z32 ) 350Z 370Z Parts

anyway after installing it i am noticing a loud deceleration pop at the exhaust which i didnt had with the former exhaust system. so i tightened the tailpipe rear and front clamps as there is no gasket in that área. the only 3 gaskets that come with this exhaust system are the manifold to downpipe gasket and the two pipe to pipe 2.5 inches gasket. I even lowered the mixture to 1.5 turns clockwise to lean the mixture and there is still popping at the exhaust. I guess i will need to purchase a set of better quality gaskets:

3 Bolt 2.5" Exhaust Header Manifold Collector Flange Gasket Graphite Aluminum | eBay

I really hate that exhaust popping sound at deceleration and mostly because i did not had it with the stock exhaust. Maybe due to the fact that this is a turbo muffler its different. Anyone?