[iPhoneNerd]

Originally Posted by SinginHawk

The Z/28 and Ground Effects diffusers are identical, and the most expensive at around $800.

The ZL1 diffuser has a unique design, and a reasonable price at less than $300.

The 1LE diffuser is the cheapest of the lot, at around $100 before shipping charges.

There is no such thing as an "NPP diffuser". In fact, all of these could be considered "NPP diffusers", since the NPP exhaust has 4 total exhaust pipes (2 on each side) and thus requires a wider port, which these 4 diffusers (1LE, ZL1, Ground Effects, Z/28) all have.

The stock SS/LT/LS diffusers (without NPP exhaust from factory) are identical, and simply don't have enough space for 4 exhaust tailpipes.

Aesthetically, only the Z/28 and Ground Effects diffusers look much different from stock. You can always just have your diffuser sanded and painted if you aren't planning on getting four tailpipes.

Thanks so much for the info! Yes I will be going Quad Pipes.