I agree on the gauge. If it makes 200 psi it makes it.....the gauge not being able to hold it seems irrelevant to me. I'd be looking at the injectors now. I'd start by moving the "dead" injector to another hole and see if it misses there.

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.