I've used Flowmasters for decades now,
I currently have Delta Flow 50's & a mandrel bent FM system on my 68 RR 479ci/6bbl,
with full 3" exhaust out the back, I like the sound & performance aspects...
don't go to big of a pie for your "actual" needs,
also use a H-pipe or X-pipe, located where the pipes start to cool,
you won't get a bad a drone/resonances...
Different strokes for different folks !!
100% Made in the USA
I found something that "actually" works very well & doesn't rob HP &
actually has a scavenger effect, has great sound, they were the 1st real race mufflers &
were orig. produced in Santa Rosa Ca., by a local racer...
I stick with what I know works...
Far from OE look, they are a performance muffler/system