Flowmaster 40's vs Flowmaster 40's

My friend juts recently bought a 89 k1500 pick up with dual flowmaster 40 series exhaust. He has the original manifold. I on the other hand have a 454, with hedman hedders and flowmaster mufflers as well. His mufflers seem alot louder than mine. When he drives his mufflers sorta sound like a "pop" . (not back firing). plus i can tell its louder. Does he have the Flowmaster American Thunder mufflers and do I have the Delta Flow ones because my mufflers should be louder than his with the headers i put on. please answer....

the origional 40 series muffler is the loudest one they make. I have delta flows and they are definatly quiter than then orgional 40's. I honestly doubt putting headers on would make a truck much louder at all, maybe just a lil.

the delta flow ones are much deeper... so they dont sound as loud... who cares if some one else is louder, yours sound better

ya...i guess your right. there is no sense of putting those other mufflers
on there, i kinda like my sound better than my friends. They are alot deeper than his. it wouldnt be worth my money to put new original 40'
s on there.