Here's the plan. I'm going to be putting some LG Motorsport Super Springs on the car in the near future. This will be 1 3/4" roughly. I'm thinking of getting a Mufflex system for X-mas, and am wondering if the 4" will have clearance issues. I'd rather go duals, but I had 3" TD's scrape on my stock susp. 02 Z28. Any lowered guys running a 3.5" or 4" system?

 

I ran the 4" with no problems from a 3" y with a 3' to 4' flowmaster collector.
Had dual electric cutouts on each side of the y and had no problems with clearance. My springs were cut about 1' as well. Hope this helps.

I have 2.5 duals all the way out the back now and it totally blows away that mufflex. Get the Mufflex if you are planning to move air! Like a turbo setup.

 

Duals out the back might be a good choice too. I just need to keep it halfway quiet inside the car ( got a baby due in May). 3" TD's dumped with 1chamber Flowmasters was too just too loud. I was thinking the Mufflex b/c it's got a good sound and flow, but not too loud. What mufflers are you running?

 

I have the 12 inch twisters on it. but yeah, out the back is the way to go. only loud if you drop the hammer on the throttle. Doesnt really even drone.