I think he meant "these mods do not affect engine breaking in a negative way"

He also mentioned:
"JWT flywheels have been reported to add inerita and take a way engine breaking.
some have evn said that adding an additiona UR crank pulley has added to the loss of engine breaking. Those mods are not good."

That's why I think he meant it wasn't affected in a negative way.

 

+1 on that
crawford and kinetix both make nice packages

 

Stock Z sounds like crap anyway. After Plenum and pop charger my Z sounds so nice its like day and nite diff and now I cant wait to put the topspeed exhaust on.