I am having a small issue with my 440 missing above 5000 rpm. It is in a 67 GTX with a 5 spd tranny. I have 10 3/4:1 comp, a solid cam with 242/252@ .50, heddman headers, performer RPM, 750 holley with proform main body, pertronix ignition and flamethrower coil. I just recently had the motor out doing some detail work and the only thing i did with the engine was adjust the valves. It seems to run hard up to 5k and then acts almost like a rev limiter and misses. Once I shift it seems to be fine. I have checked the carb and the secondarys seem to be working fine. i guess my question is, is this an ignition issue (double checked and the pertronix is getting 12v)or could a valve be hanging open or floating? I'm pretty sure it didn't do this when I pulled it out last fall. thanks for any help you might provide.
-karl