not very true.. they will gain you maybe up to an almost 200 hp like mine (most cases are around 190, 195hp) , but then you also need a decat exhaust, inlets matched and an uprated airintake to go with the cam-job.. No MASSIVE gains to be had with cams.. All they realy do mostly is chnge your powerband, the rpm range where all the torque happens
You should/could also be looking at the new inletmanifold by Angelworks, look at the "supercup" thread and read up. This will be a nice value for money for you !