I have a 99 f250 6.8 v10 and was wondering what have other people been doing to the exhaust as far as a preformance cat and y-pipe? So far I have installed a cat back exhaust but want to go from the car forward

 

Cat forward?

 

Yes sorry typos

 

The best cat forward setup would be a set of long tube headers like the Banks or Thorleys, which both come with a good Y pipe. If the headers don't fit the budget, then look into a smooth flowing Y pipe like the SPD that 5Star sells.
1999-2000 SPD Y-Pipe Superduty / Excursion 5.4L / 6.8L EX9900AL SU9900AL - 5 Star Tuning

 

Is the cost for headers really going to be worth in on a 17 year old truck with NPI heads? Can't really flow better if the intake port is the biggest restriction.

 

Good point on the non-PI heads, I forgot about them not breathing as well as the PI version. The headers are expensive, however they did help to wake up my later PI V-10 a little.

 

Th eheaders will help with low end power and get rid of flutter. Not to mention get rid of the exhaust manifolds and studs which break regularly. My Thorleys made a noticeable power difference but they were rather expensive. Keep in mind I also had the later more restrictive y-pipe. The 99'-early 00' ypipe were not as the restrictive. But all the 2V trucks got the same crappy exhaust manifolds.

It all depends on how long you plan to keep the truck, what you are ok with spending and if you are willing to deal with the few negatives of headers.