I've got a 91 Z28 1LE 5.7 auto. Question when i purchased the car it already had a AFPR on it. After freeing up the exhaust like with headers, performance cat-back system and some intake work done I suppose the car will run much leaner. I heard that running higher numbers will reap greater dividends. My question is should i lower the fuel pressure to run a little richer or raise the fuel pressure? Where to start? Also what is the best air/fuel ratio mixture. Is there a way to tell air/fule ratio while driving car iat WOT?