My friend has a 68 chevy truck with a 99 LS1 in it. Have fuel all the way to the rail and everything works but the injectors. You can keep the truck running with some starter fluid but you know how that goes, just for a few seconds. We too k the PCM out of the Porsche 914 and put it in the truck just to see if that was the problem but still no luck. What would keep the injectors from firing that you guys can think of? It has the fuel filter with return line and like I said 60 psi at the rail with plenty of spark to the plugs.