I'm in the process of upgrading the MPI kit on my 258 w/ 4.0L head. I'm installing Hesco's enlarged throttle body and adjustable fuel pressure regulator, and I would also like to install some larger injectors. Bennie, (@ Hesco) told me that the largest injectors I should go with are 21 lb. (the stock MPI inj's are 19.7 lb.). I've been told that Ford 5.0L inj's are a direct replacement, but I've been unable to confirm this or find any rated for 21 lbs. Does anyone know where I might find specs on fuel injectors so that I can track down a direct replacement for the stock inj's?