Or does it even matter? I had to replace the diagphram and now my FP seems a little high and turning the screw makes little differnce. As a matter of fact Im pretty sure the screw is backed right off and the FP is just under 60 psi. Aftet the engine warms up it gets down to around 52-55 vacuum hose off.

I also just installed a 255 Lph pump. I'm not sure if I have issues with the fuel pressure gauge. Its a liquid filled Marshell. The pressure on shutdown drops to 25psi quite quickly then sits there for a whle before dropping right off.

Yesterday when I blew the diagphram, I notice there was still quite a bit of pressure under the cap 40 minutes latter with the guage at 0. I had to pinch off the vacuum line because fuel was spraying out of it hard.

Doesn't matter. You just got a new fuel pump so the pressure is staying high which is good.

Did you make a AFPR out of the one you had, or did you buy a new diaphragm? I just replaced mine with a Holley a few months ago because the stock unit was spiking it up to 55psi and I was getting vapors in my house at night.

I have the accel unit which is just the black cap with the screw on top and metal shim unerneath. I just replaced the diagphram. Is there anything that can go wrong with the actuall aluminium block that the diagphram sits in? Im talking about the piece that you screw the black cap down to.

Sounds like maybe, something didn't seat right when you did it. I didn't want to go through the hassle of what your going through so I just bought a holley and slapped it on. No issues.

Does this replace the whole factory assembly?

Sorry for the delay, yes it does. Nice brushed aluminum unit.