Sparks x-6 v. x-4

[ST87]

Is the x-6 louder than the x-4 i know the x-6 is supposed to open up more for more modified engines and all but i saw a a pic and it looked like the x6 was shorter meaning it should make it louder is it really shorter or is this just an a illusion.

[cals400ex]

they are the same length. well, as close as i can tell anyways. both sound pretty much identical to each other. the x-4 everyone says is not worth it yada yada yada.... it worked well, really well, in my opinion. we ran it on a very mild 406 and a 416. the x-6 just doesn't have the torque as the x-4. the x-6 likes high rpms, the higher the better.the x-6 does rev really quick in the lower gears, if the rpms are up. i ran the x-6 on a few motors. on the 426 it seemed to do alright. i don't know if i would get it again, but it worked fine. i would consider the hmf. it seems like they put out decent power.