I use a walbro 450 pump on stock lines and 80lb injectors with Eric's 5.7 chip. It's hotwired, and I have a casper's volt booster. I switched the return and vent lines, which was easy. I replace all rubber sections of fuel line every few years with new fuel injection hose from auto zone. 30psi with a Te44 turbo for several years now no problem. I'd say get an e85 chip and as long as there is no knock, keep turning it up until you've hit your leanest comfort zone. Mix in some 93 if you need more room. By way of example, I don't go leaner than 11.5:1 on the wideband, but I've hit 12.2:1 before and still saw no knock. E85 is great.
Edit: just use the setup you have now and see how far it takes you. A 255 pump/60's/stock turbo can probably hit 23-24psi on e85 with zero knock and be real fun on the street.