[olddog]

Well I'm no expert on blowers, but I have read a little on the subject. 19# is pretty small. Ford steps up to 24# on the 32 valve 4.6 which was 280-310 hp depending on the model. I think they were pushing the 4.6 up to 375 hp with the 24# injectors and I am fairly certain that at 400 hp they definately go up to the next size injectors.

You can cheet a little by increasing he fuel pressure and get a little more out of a given injector. However the next issue is always fuel line sizes and fuel pump size. You cannot just stick in bigger injectors, push a bunch of air, and go with it. The whole fuel system needs to be abble to supply enough fuel at the correct pressure.

It all depends on how much pressure the blower is pushing and what other modifications have been made. If your pushing much more than 5 psi there better be an intercooler. The computer will need a chip to take some timing out at higher boost to prevent detonation.

With all that said, as long as you do not stick your foot into it, it will be just fine. As long as the manifold stays on the vacuum scale (no boost) the injectors will not have to deliver any more fuel than it would without the blower.