I don't think I would put a line filter on before a fuel pump if it were me. If you stop up the filter you could destroy a expensive fuel pump. Worse yet the engine could run lean and you could cause engine damage. You didn't say if you have fuel injection or not but I am assuming that you do as Excalibers comply with DOT regulations. I also assumed that you have checked the usual stuff out. I.E. fuel filter, regulator setpoint, return cannister, return line, and so on. If all that stuff checks out, (and you have a external fuel pump away from the gas tank) I have used a small SURGE POT before the fuel pump. Just make sure the line comes in high from the gas tank and goes out low to the fuel pump. You will need a air bleed on the top of the pot to fill it up before use. I have also used this surge pot in the past for a secondary racing fuel tank. Just switch a valve to the race tank you are using, arm the NOS system and go racing. Switch back to your regular gas tank for your trip home. Bet that will get rid of any fuel starvation problems you have.
But I'd really bet that you have a weak fuel pump though, or some such thing, as that Excaliber did comply with all rules/laws and emission laws for cars that year. That usially means something redundant has gotten weaker since your car was built.
Bet it's just out of warranty too!
PS- watch that return line going from that racing fuel supply. It could fill up your regular gas tank. A secondary return line is in order.
cobrashock