ill be getting true duals here in a couple weeks hopfully and iv got a few un answered questions.

i want to eventually put out about 550rwhp on motor and then have a 150-200 shot on top of it.

this exhaust will be ran all the way to the back. im deciding between 2.5" or 3". if i go with 3" im gonna need a phb relocation kit. so thats another 200 bucks. idk if 2.5" is enough.

the other question is about mufflers. i was thinking magnaflows because i want to have a comfortable exhaust to drive with for a couple hours at a time. magnaflows are really expensive tho. anyone have any alternatives?

 

Lots of info out there, no really 'true' numbers. That being said, It's my understanding that dual 2.5" with a balance tube or X pipe to help with scavenging/reversion is good up to about 500 flywheel HP. Along the same lines, 3.0" is good to about 800 flywheel HP.

BMR's PHR004 relocation kit sells for about $200.00. Not bad if you're probably going to spend close to a grand for a good stainless exhaust system... have a look at the pics installed on BMR's site- http://www.bmrfabrication.com/F-bodySuspension.htm (about 2/3 way down the page)

Think about glasspacks- around 22" body length, 4" body with 3" in/out tubes. You can fit 2 of them and the right > left crossover tube in the back in the same space as the old single muffler. You don't have to beat in the floor under the back seats or screw around with the fuel lines. Here's a few pics of my setup. I have 3" to the X pipe and then reduced to 2.5" with glasspacks arranged as outlined above. Note the tight squeeze with 2.5" over the PHB. I'll try to post a vid but there are some good quality "LT1 true duals glasspacks" vids on youtube: