Need tuning help on 340

It seems to me, if you can get the AFRs down at 12, your fuel system is keeping up.
The 160PSI is indicating a good Dcr, which the 218*cam is trying to achieve.
At 3450, 96 mph is pretty good for an LC 340 with a tiny 218 cam.
If your power-timing is down at 32* or less, to avoid detonation, that is hurting your mph.
What your tach at,crossing the line, and in what gear are you. That makes quite a difference.With a 218 cam you probably want to be trapping at 5400?Or less even. If you are winding it out too far, that could really be hurting you too..

But really , you need to figure out why 32* is detonating.
Are you running oxiginated gas?And what grade?

Heat is the number 1 cause of detonation.Or rather too much of it, in the chamber. Low Compression, open chamber heads, also have trouble with pressure spiking too early.

Ok something is not right here;
I plugged some numbers into the Wallace calculator,and I can't make the numbers come out with your inputs. This is what you supplied; 160psi, 218 cam,8.5 Scr.. No matter how I fudge the numbers, I can't make the 160 psi.
Can you be a little more specific as to the cam? What I need is the ICA; Intake Closing Angle, or an advertised intake duration plus I need the LDA;Lobe Displacement Angle.Then are you absolutely sure the cylinder pressure is 160psi, and that the 8.5Scr is accurate?
Sorry, I could not find the "BracketMaster on the Lunati Website.

I did manage to make it work with 10.5 SCr, a 66*ICA, and got about 165psi. This would be a 284/108 cam in at 104*. But the .050 on a 284 cam is more like 236 to 240;no where near 218*.In any case, this yields a Dcr of 8.23 which as you have discovered is too much for pump gas, and iron heads.