Need an educated opinion

[larry may]

Here is what I did. For the sake of saftey I removed the Electric fuel pump and installed a competive mechanical pump. Since that time this ole heap does not idle like it did before the swap. Also will stop running at a stop while in gear idling. Has to be feathered constantly.
From a dead stop on up the to the top it runs very well but not quite like it did before. So before I change back to the Electric I need some feed back . The mechanical is GM used on the like HP 350cid. during the muscle car years. I had thought it would feed this 4777-4 1145x2 pumper holley just fine.
However; the camshaft is a few notches above the old school stuff. I'm also running a notch above true blue octane. Might be 106 + or so. Thanks for any helpful solid information, May be one of you wizzards can work with this to help get me back on track... Larry