We installed a 1" tapered spacer before pull #7 and that fixed the flatline. We tried 4 different spacers and even stacked 2 .
It was getting late and we never tried changing the jetting after pull 7. Maybe dropping 2 all around might help the afr and BSFC ?
I checked the rotational torque of the shortblock and it was 25 ft-lbs or less. Lowest my wrench will go... so I dont think friction is the issue. Could be the intake creating massive turbulance ?
The engine liked about 32* of timing so that should mean the chambers are efficient.
