You've got about another .7 -.8e.t. From your best so far. Are you logging anything? Have you verified timing? What a/f? What is the converter flashing to under the highest boost you will run it at? The 218 grind is not ideal for your combo and will peak around 5500. You want the flash stall speed over 5300. What is the converter slip crossing the line? The 61 will continue making power to 32-33psi and 5500 rpm. I went 10.61@127+ with a smaller 60-1 and similar heads with no porting only bowl work and valve job. There is probably .4 in the converter and gearing and another .3 with more tuning. I'd run 116 and a small shot of alky to get the most out of it.