Alright guys, I need some help. Right now I have a holley street avenger 570 on my 283. Initial timing is 10 degrees advanced and all in at 30 degrees at 3000 rpms. from a dead stop it bogs down until about 2500rpm, then i supposed the secondaries kicked in and she accelerated much better. I changed the secondary spring to the stiffest spring to keep the secondaries from opening and this helped immensely but there was still a slight stutter. The idle mixture screws are turned out 1 and 3/4 turns. I threw on an edelbrock 600, part # 1406, and it ran much better. It didn't seem to have as high end acceleration but at least it accelerated without any hesitation or bogging down. WHAT gives?!? the edelbrock has bigger jets and a larger cfm. I'm spinning my wheels trying to figure out what else to do! PLEASE HELP.