BradH, What calculator did you use? The one I have always used here https://robrobinette.com/et.htm shows you needing 740FWHP to run a 10.5. I used to use the Moroso slide rule , but nobody I knew ever seemed to agree if it was actual RWHP or engine HP you were using to calculate E/T LOL Seeing your numbers gives me hope that 675+ FWHP in my E body that weights hopefully under 3550 race weight could run a high 9.