Originally Posted by fatgump
It just flattens out.
I am running dual springs that came with the Darts. My timing is at 35@3000 RPM. I have the MSD 8361 Pro Billet.
Have you changed any springs or bushings inside the distributor? Rev it on up to 3500 rpms to see if adds more timing. You should be able to rev it to 3500 and the timing stays at 35*. What is the timing at idle? What octane gas are you using?