I had the pleasure of installing a set of JBA headers part number JBA-1850S and a JBA catback part number JBA-403005 on my 2000 5.3 reg cab this week. Talk about a cakewalk!! I had the catback on in an easy half hour in my driveway, and the headers in 2. I also took the time to go ahead and have a muffler shop cut my factory cats off and install some Pypes 2 1/2" part number PYP-CVM10 replacement highflow cats. The truck sounds great! Nice low tone with no popping or "glasspack" sound. I haven't had an opportunity to put any numbers to performance or economy yet, but I can tell by the throttle response and mid-range pull that the truck is making more power. The quality of the JBA headers and catback are the best I've installed (and I've installed a lot of exhaust). Highly recommended!!!!
The only downside to the whole job is that my check engine light is on. It came on after the cats were installed. I think either they're throwing the o2's off because they're flowing so much better than stock. That seems to happen on mustangs from time to time. I've reset the light. I'll see how long it takes to come back on. Maybe just a fluke.
Overall, very excited about the swap.