It rpm's fine just doesn't make any power up there and it's together and running, not in need of a rebuild just looking to add a bit more punch to it. but thanks for the suggestion
Heads are probably the issue, the exhaust seats in an old 360 burn/wear away and the valves sink and flow horrible.
Cam it and let us know.. but before you do...pull the valve covers and rockers off...and put a ruler across the stems to see if they are even or some higher 'the exhausts' .