Disappointing dyno results

Kindof beatin a dead horse but just for reference.
Stock engine dyno with manifolds run by Hot Rod in '69 back by one of the rags, and stock rebuilt engine done more recently by a different mag had very similar numbers. That said, don't expect numbers from one dyno to another to be a real comparison. However shape of curve should be similar.
First three pulls plotted here.
1969 Magazine article with the dyno runs posted here
https://www.forabodiesonly.com/mopar/threads/mopar-manipulatin’-hrm-august-‘69.496107/