Hey guys as stated above ive put s holley 750 double pump on my 5.0 over carbed i know but the car was stock and now i have an 80ish qjet intake on it i put a block off plate for the egr and im using the factory pump on a toggle switch (used the relay plug to bypass it incase i still need to use it) but im running a spectre fuel pressure regulator i got from autozone and with my fuel pump on its pushing fuel through the jets on my carb and the psi guage is showing 20 psi ive tried adjusting it up and down and it seems not to change the psi when i turn off the fuel pump the psi goes to 0 and i can only keep the car running when its about 2500 rpm any lower and it will stall but start tight back up any idea why its doing this i couldnt find any videos or anything on the fpr or really how to run them.
Thanks in advanced

 

I did a quick check on their website and it looks like the two spectre fuel pressure regulators are good for "under 15psi" and not for fuel injected vehicles. The stock TBI pump could be putting out close to 15psi (10-13 is normal I believe). Knowing the junk that Spectre makes, I wouldn't be surprised if the stock pump is just too much for the regulator.

 

Update i got the psi down to 6 and i still cant keep it running unless its at 1800 rpm anything less it will die ive used a vaccum guage to mess with the idle air screws got it to the best psi then tried to lower the rpm to lower and it stalled slowly