a P-pump conversion is very labor intensive, and you have to fight the electrical gremlins also. a member on here who owns his own shop, and sled pulls a lot, named TSterner did a p-pump conversion on his truck. you have to re-machine a new front cover of the motor.
a dual CP3 kit such as Relentless, ATS, or PPE's is a better way to go, I think. They have taken out the guesswork, and done their homework out of running out of fuel pressure in the rail.
hope this helps