With Indy heads, I'll bet. I found that my 416 (albeit dished piston, 89 octane pump gas street motor) with an Ultradyne 259/263@.050" .590" 110LSA flat tappet solid didn't want or need all that RPM with regular Eddy heads. It really was no faster shifting as high as 7200 and with carbs as big as 950, than it was shifting at 6200 with 750cfm. The limited airflow and long stroke characteristics were holding me back. I was running a 3000 stall 9.5" 904 converter that became a 3500+ stall after switching from 3.58 to 4" stroke. Good luck!
