LS9 engine
 

Am going to put an LS9 engine in a 56 chevy. I am being told it requires a specific fuel pump and variable fuel pressure regulator? Would appreciate any information about this.
Thank
Dirk Hubbard

I would assume the information is correct. If you are buying a entire LS9 from GM, in which case it will come with an ECM programmed to work at certain fuel pressures and so forth and it will, essentially, need that pump on the other end of the fuel supply. Concievably you could use another pump that could produce similar pressure/flow/change in flow rate on command as needed, but you might have to re-programm the ECM and it would not be worth the trouble, in my opinion.