Hello all, awhile back my neighbor recruited me to help work on a 48 ton and a half with a late 50s 261. After giving it a tune up, carb swapping and fuel pump it starts and idles fine. Anything above 1/4 throttle and it starts missing whether or not it's under load almost like you flip a switch. We're both scratching our heads on it. Exhaust is unrestricted, can't find any vacuum leaks, and timing is set correctly. The vacuum advance port is capped at the carb because of a bad diaphragm. Any ideas on what to check?
Thanks- Jordan
