The carb being rich is one thing helping to keep this engine out of detonation with 10:1 compression and 40* of timing! Those 670s are fuel hungry. Modern fast burn chambers may start to roll coal at 8:1 AFR. I imagine that if you leaned it out to about 11-12 AFR, it could start to pick up a few degrees of ping near peak torque. But yes, going to about 10.5 AFR in that region should be safe and may pick up a few ponies.
__________________
I could explain all this to the girl at the parts store, but she'd probably call the asylum.
White '67 LeMans 407/TH350/Ford 3.89... RIP
Red '67 LeMans. 407/TH400/Ford 3.25
|