Originally Posted by 71fj40guy
I'm getting valve chatter under load on my stock 290 hp GM Perfomance 350 crate motor.
I have replaced the plugs, plug wires, distributor, and did a full valvetrain check and valve adjustment just in case.
Its running a late model Rochestor Quadrajet carb with electric choke. The only aftermarket parts are a set of aluminium valve covers, MSD E-Curve distributor, Blaster coil, 8mm Autozone plug wires, Champion platinum plugs, Sanderson QP1000 headers, and an Edelbrock air cleaner.
Right now I have the total timing set at 32 degrees and 12 degrees at idle. I have also tried 34 total and 14 idle too and it still chatters.
What type of noise are you hearing is the valves rattling or is the engine knocking from detonation.
Have you adjusted the valves.