Hey guys, I'm having some trouble getting my '72 240Z to accelerate without "machine gunning". I've searched all over the site and have not found suitable answers. It's a 3.0l race motor, 13:1 CR, triple Weber 45s, ported head that flows 227/155 CFM, 280zx distributor, summit racing ignition box(per Dave Rebello), new coil, carter fuel pump, Rebello road race cam grind. I had my timing set around 15, 35 advanced. I advanced and retarded it from there and the problem remained. As I accelerate, it doesn't have full power and makes stuttering/machine gun sound. It's not a mechanical sound, like a rod knock or broken rocker arm, but sounds more like ignition or fuel related. Also I am running ngkbr9 plugs and 110 leaded fuel. Any help or suggestions as to a cause would be greatly appreciated.
Thank you in advance, Andy