When my Big Block is really cooking just right, it makes a slight spitting sound. Took a while to get used to it but, I know it means its running slightly rich which is just where I want it.
That is the advantage of being overpowered; I can throttle back and still have plenty of muscle. It also makes the runs very consistent because the Saito runs cooler. They last forever like this.
Some Saito's, especially the ones running a baffle, make that beautiful "phutta phutta" sound. Mine sounds like a Harley Davidson growl.