New to me 73 Cuda, didn't run when I got it. I replaced the damaged fuel pump on the 340 with a no-name pump from Auto Zone. Tank, sender, fuel line, and filter are all new. I have a gauge on the Earl's feed line to the Holley 650 DP. When I start it up cold, the needle is averaging 7psi. Of course it's bouncing about +/- 1psi on either side of 7, which I assume is from the diaphragm type pump. Car idles OK but not great, with a miss here and there. If you put it in gear it won't idle, wants to die unless you wait 5-10 minutes for a full warm up. At that point the idle has smoothed out and when in gear it idles fine and drives fine. At that point, the gauge is showing about 5 psi. Go for a drive and it's fine at stop lights and everything runs pretty decent, get home 15 minutes later and the gauge is at about 2.5 PSI. But still idles fine in gear and out. WTH??

I know my carb adjustment isn't perfect but it's pretty close. Timing is at 14 intitial, probably could go a couple more degrees. But what worries me is the high pressure at start, which I think is affecting the idle and then the drop off as the engine warms up. Or is this normal with a mech fuel pump? What should I be seeing? I have a Holley fuel regulator I was considering installing to see if it smooths out the pressure, but it can't boost it if it's dropping so much.