I agree with the cats, now knowing that they make them now with little to no resistance I will def be shopping, in regards to removing the muffler, any other way to get a deeper sound with out headers? 225 slant
I went to a low restriction turbo muffler and a 2ΒΌ" pipe on my 73 /6. I also went to an oversized exhaust manifold w/o a heat riser. The bigger pipes definitely deepen the sound. Although at highway speeds, the exhaust noise is no worse inside the car than a stock system.
If I had to run a catalyst, I'd probably do the same thing except go to one of the straight thru Dynomax mufflers, or maybe even a glass pack.