if you put in a really heavy cam it will have a tiny bit of v8 rumble to it.. my buddie has an 05 viper with custom duals so they dont join anywhere .. with a heavy cam.. and at idol it has a tiny bit of rumble kinda like a v8 neat...... i think the problem with the custom duals that you are thinkng of .. is every hemi in town has it.... i think the single side duals kind of sets it apart from the hemi...... so ppl know its different...well thats my opinion anyway