45 psi?
 

I was looking at this lift pump http://www.dieselsite.com/index.asp?...ROD&ProdID=475 Is it too much for the injection pump, or will it simply bypass the extra pressure back to the fuel tank?

if im correct it is too much. dont think you should have more than 20~

Use it with a regulator set at 14 psi. It will last forever because it is loafing.

I have been running this pump for 5 or 6 years. It is designed for operation with diesel and uses a stainless steel pump mechanism. It is rated for 40 psi but will easily top 100 psi. A bypass regulator will be required. It uses the diesel fuel flowing through it for cooling.
It is a good idea to use a resilient mount when bolting to the frame. It can be loud. Also don’t skimp on hose size. This pump moves fuel and must have a -10 AN pick up tube (5/8”).
I use a circuit to slow the pump down to limit the pressure but that is another story. If interested, search for PWM pump controller on this site.