Originally Posted by DDTCM
You pretty much have shortys from the factory with the work that they put in on them. Go with LTs for more gains but there have been people running a O.R. X and seeing the same gains as LTs for less $'s.
Yes and no. LT's with O.R. X will make more power then just an O.R. X pipe. BBK shorty's with X pipe has made just as much as LT's with O.R. X pipe. The power is just in different rpm ranges. I know I have a buddy that runs shorties compared to my LT's. His car has also been compared to LT O.R. X pipe cars that had Kooks/ARH/SSW systems. He made same power as them as well on the same dyno same day.
Where the LT's is going to shine is FI or when you go cam and heads really. They will move more air in the long run. The BBK shorty headers did make more WHP over the stock ones as well. Also Some thing to think about is if you go with the Shorty headers you still can put a turbo system on with out changing headers again. LT's you can not do that.
If you are just building a street machine I would go with shorty headers as the power band isn't as high. If building for track go with the LT's. If you have any plans of a Supercharger go with the LT's.