At about 600 horsepower with JDM built long block and many mods. I do have the 255lp walbro fuel pumps but i am still running stock fuel rails. I have been told we do not need fuel pressure regulator for our lightnings that they will run ok without fuel pressure regulator. But i am not sure if i should change out my stock fuel rails and if so what is a good brand of aftermarket rails with place on the rails to mount regulator. {Thanks for your input}

 

Stock fuel rails can handle 700hp..

 

Does cylinder #5 run leaner than the others?

 

what do you mean? they are stock rails, same inner and outter diameter as stock lightning and naturally aspirated 5.4s..

 

JDM is out of the fuel pump resistors until next week some time.
Is thiers same as ford and if so what is the part # thanks

 

As stated by Rich the stock rails are good to around 700HP, one could run some 97 rails but they are minutely bigger at best..... J.J. has some nice new rails up for grabs..

 

#5 is at the left front, and the fuel pressure sensor is at the right rear. Just wondering if there could be a slight pressure drop over the length of the fuel rail.

 

Most likely not

 

I doubt it extremely.. I know that there were some after market fuel rails that suffered some lean issues, but I havent heard of any in a while.. I used the 97 rails with nitrous and my whipple along with 60lb injectors. I never had any lean issues. hope this helps.

 

I run about 600 HP blower only and add a 150 wet shot on top. Using '97 rails with 60# injectors. Twin Walbros and -6 lines. No lean issues at this level.
Jim

 

My fuel rails are installed and my fuel pressure regulator pressure is at 40 on idle and 62 at wot so i should be good to go. I think it is going to run better.