Does the 194/250 Chevy 6 "bark" when you lay off the gas, like the 235 using a straight-through (no muffler) exhaust?
My boys both have Chev's with split manifolds, running straight thru mufflers, they crackle/bark as they go thru the 2500 - 3000 rev range, and crackle as the revs drop down as well.. A sound all of their own.
The "bark" can change with a lot of things. Ignition timing and fuel mixture have a lot to do with it. Compression and cam specs are the biggest factor in the exhaust sound. So if you are running a stock engine don't expect it to sound like a built motor because you took the muffler off.