This is for my 1991 Z28 bone stock 305 auto vert.
Ok the fuel pump went out in my camaro today... I am currently in the process of gathering parts to do my LS1 swap, Can I install the walbro 255 lph pump in place of the factory 305 pump and run the 305 with out damaging the new higher output pump? I don't want to have to do the pump again when I do my swap.

You can probably run it without issue. The flow is a bit lower at the pressures the rail operates at, so the regulator should be able to handle the flow.

I just installed it in mine. If you look at it from Hawks third gen, Racetronix includes one in their kit with their wiring harness. I can tell you right now though, it's a lot of work getting to the fuel pump so it's better to do it right once and have enough fuel for any upgrade in power later