Timing problem....maybe.

[kylewhunt1]

Okay, here is one for the audience.  Heres some quick specifics: 383, MSD everything for ignition (8545 dist, 6a box, wires, coil). Heres the problem. When I set the timing at 10*, the car runs like crap under acceleration with full throttle. I back off the accelerator about 50% and it takes off like nothing was wrong. I readjust the timing and set it way past the timing tab (i would guess about 20-25*) and it runs better but still stumbles at higher rpm's. I dont know what the cam is but its not radical, fairly smooth idle. I rotated the crank around to zero and made sure the button is on #1. I have an EZ EFI system on it so i have taken it to rich and lean with no improvement. I called FAST and went through a diagnoses with them and the fuel injection is operating correctly so I am ruling it out. Any intelligent thoughts?

[Chryco Psycho]

the obvious is that at WOT the EFI is not reading Throttle position correctly or not sensing vacuum drop to 1" or so & not adding enough fuel or the fuel system is lacking or the ijectors are too small . But the EFI is working so . ... it seems like the advance curve is too long , you need to shorten the curve using the largest bushing to limit the advance I forget how short you can make it but say you can get to 18* curve & you want to set timing at idle @ 18 so you have total timing of 36*