Ok, if it has less than a 1/4 tank of fuel that could be your problem. There has been alot of problems with the "1/4 tank" issue with lift pumps installed without a draw staw or fuel sump. Basically it is sucking air and not getting fuel to the injection pump.
I really like my LML, the sluggish pedal known as "dead pedal" is the way they all are from the factory. Some tuning can get rid of most of that. Mine has 64k on it and it has only been in the dealer once for a ECM update for the DEF system. Otherwise just regular maint.
The heads on my motor are factory LB7 heads that were CNC ported by Wagler with over sized valves and I don't think I could make more than 1300-1400 hp with them. Spend the money now or you will wish you did!
Why don't you give us the rest of the details about your build like:
- injector's
- pumps
- turbo
- drivetrain
- A/W set up
Than maybe we can help you out more!
Yeah, it's pretty tight. I had to trim the bottom of the plastic piece's for the head light mounts. I was real close to welding the cores together, but like the idea of them not touching and transferring heat to each other.
I mounted my fuel pump to the tube that mounts the weight box to the truck. I have -10AN (5/8") in and out of the pump and than split it into 2 -8AN (1/2") up on the motor that go to each CP3. The return line is -8AN.