i got a '01 2500hd 2wd crew cab, short bed & 6.0l. i talked to someone at Flowmaster about which mufflef to use, they told me to use the big block 50 (3-chamber, dual in-dual-out), but i thinking about going with the 2-delta flow 40 (2-chamber, single in-single out). the 50 is pretty big, compared to the 40 , they said i would lose too much back pressure with the 2-40s, butthe 50 (3-chamber) isquieter than the 40 (2-chamber). the volume of the 2-40s is less than the volume of the 50, but if the volume (2-40s) is less, how would there be less back pressure. i don' tunderstand!!!! if any one can help me out, i would appreciate it.

 

I just installed the 50 on my 5.3 2000 Suburban. It is not very loud but that is O.K. has my wife drives it primarily. I did notice a slight increase in fuel mileage.