The TPI motors flatline at 4800 RPMs, due to the port design on the heads. Change the heads to a set of Vortec heads and put on a baseplate for the vortec hook up and change the profile from 4800 RPMs to 5600 as a top out. I have a motor that I did this to and then sold it to a friend. The intake change and the new injectors produced a 375 HP motor with a lot of torque.
A TPI 350 settles in around 240 HP in stock form, and has a lot of pick up that a carb does not have. That is due to the design of the injection and the use of ALL of the cylinders at their peak fuel charges. A carb motor is lacking on fuel charge at the outer ends of the intake manifold so there is losses in the perofrmance in those cylinders.
Go the the Jags that Run website and they ahve an install book that has everything that you would want to know and a list of parts that will holp you install.
www.jagsthatrun.com