ground and shaved stock headers and back... help?

[SeanWilson]

okay guys ive got a 98 4.0L, since i have a couple snapped exhaust manifold bolts and desperately need to get rid of the previous idiots hack exhaust job. My plan was to pop them off, port the edges and get a little better flow right out of the block and then start with a new y-pipe and back, popping out before the rear tire.

Question 1. while i am in there, can i remove the EGR rebreather section?
~of course welding a patch on the exhaust and blocking off the air intake.

Question 2. if im bending a new y-pipe, what size pipe should i use?
~this is my DD and play rig

Question 3. i will be running a thunderbolt-spin cat converter into a 3” flow master 44 ( free69 ) that will be choked down to a 2 1/2”... So from the y-pipe coupler back should i run it all 2 1/2” ?


my thoughts where do do something similar to this picture, its a fellow TRS member but i cant remember who, and he has a v8

AND YES==> i will be running O2 sensors and catalytic converters, i aint green peace here, but i know these engines need them to run properly, so no durby style exhuast set up for me

 

[JohnnyO]

okay guys ive got a 98 4.0L, since i have a couple snapped exhaust manifold bolts and desperately need to get rid of the previous idiots hack exhaust job. My plan was to pop them off, port the edges and get a little better flow right out of the block and then start with a new y-pipe and back, popping out before the rear tire.

Question 1. while i am in there, can i remove the EGR rebreather section?
~of course welding a patch on the exhaust and blocking off the air intake.

I tried that once on another car I had but it messed up the fuel mixture, causing it to ping real bad. When I backed the timing down enough so it wouldn't ping (this was back when cars had distributors) it ran worse than it did before.

Question 2. if im bending a new y-pipe, what size pipe should i use?
~this is my DD and play rig

I would use 2".

Question 3. i will be running a thunderbolt-spin cat converter into a 3” flow master 44 ( free69 ) that will be choked down to a 2 1/2”... So from the y-pipe coupler back should i run it all 2 1/2” ?

On a 4.0L 2.5" pipe will be fine. It's not like you're running a Chevy big-block.