kiddcline

Which is better?

LovetheTide

What do you mean by better?

The 40's are luder if thats what your asking.

But, if you want performance you'll lose some tq. on any flow's

Ty

40's

92custom

i got da super 40's

mhiggs351w

super 40s

lynn97

40 series with no turn downs will sound great and be louder but not to loud because more than likely u have 4 converters and 50 series will not be loud at all

Ty

you will want some sort of turn down, at least a 45 before the rear axle, like my truck or you will have NO backpreasure

than again, with a muffler you should be okay, but you will want something to get the exhaust gasses away from the truck.