I have been having problems with my 91 Camaro Z28 5.7L TPI auto stalling on me randomly after coming to stops while it still in gear. I decided to start checking stuff and noticed that my fuel pressure was bumping around crazily between 25 to 52-3 psi. I have put an adjustable regulator on it and have it set at 52psi with key turned over and engine off. It will hit that as soon as the key is turned over. My question is would the fuel pressure jumping around like that cause my car to stall after coming to a stop. Also I've replaced my fuel pump with a 255lph intake pump with the INTANK fuel filter. I haven't yet changed the inline fuel filter due to not know what size and specs to get. If someone has a link to an inline fuel filter that would be recommended (plan on pushing around 400hp) or atleast the size that is needed.

If the inline filter is replaced and the fuel pressure continues to jump around what else could explain the fuel pressure moving around like that?

Thanks for any info,
Andrew