I installed a Pace setter Header on my 4.0 awhile ago. The diffrence from the stock manifold is really noticeable. Up hills and take off are really improved and now am getting 300 miles to the tank with 33" tires. The best thing i like about it is that it ran the pipes in front of the oil pan and around the side so it doesn't stick down below the tranny like the stock pipes did. The O-2 sensor is moved in front of the oil pan and protected better. Total cost was 189.00 install time 2 hours.

is that one of the dual outlet headers? or am I thinking of a diffrent brand.

it has two outlets from the header it self but comes with the Y pipe to adapt to the stock exhaust.

yea that is the one I was thinking about. Where did you order yours from?

You can get them through summit and essentials. Pretty cool if u want to run dual pipes, seem to hold up fairly well.