I have the heat coated JBA's. There are cheaper models but like previously stated thinner steel and won't have the vortex whatever thingy. Installing was an extreme nightmare and worth the crazy price to have someone else do it. The shorty's fit on 4WD, longies don't. They made a "HUGE" difference on my '04 XLT Scab. On JBA's web site it shows a 30hp flywheel dyno chart gain. I did not want to spend $5k on a supercharger even though I would like one and possibly may still do it but that won't be for a while and the headers will only improve the flow.