Flutter below 2k rpm

furrystump said
what step up springs are in it? I run a stock 68-69 340 intake with the divider cut down to about 1/2”. At the problem rpm you could be “floating” the step up springs.

Stock Orange spring. I can try a lighter spring.

512Stroker said
What do the plugs look like?
Where is the timing mark on the plug ground strap?

With the ethanol in fuel now its hard to read plugs... they always look white.