I am new to the forum. I am changing my 351w from carb to EFI. I am using factory Ford 5.0 H.O. upper manifold and 5.8 lower manifold by using BC Broncos adapter. The long block consists of .030 over 351 block,iron 351 heads w/2.02 160 valves and roller rockers. A 272 hyd. flat tappet cam, forged flat pistons and long tube headers. It is going in my 76 Bronco rock crawler that weighs aprox 5000 lbs. w/4:56 gears and 39.5 tires. Not exactly a Mustang. I am installing a performance products 70mm throttle body and Ford 70mm mass air w/ 19 lb. injectors and a new 89 mustang factory style submersed fuel pump. I'm going to guess the carbed version produces 260 to 280fhp. I don't expect the factory manifolds will support much more hp than this so, hp is not my goal. Clean, reliable performance is my goal. My buddy is thinking the 19 lb. injectors will not flow enough and keeps muttering something about calibration with the TB and MAF. He says I may be able to convert to adjustable fuel pres. reg. and just crank it up a bit to let them flow more fuel. I worry about duty cycle. Are we in the ball park, or out to lunch?