dyno #s seem low ?

The intake is not much better than a stock 71 intake, the carb also is about a draw with properly set up thermoquad maybe the quad is slightly better in the HP department. Can't comment on cam don't know the grind but that should be a good improvement. Headers should be good for 20hp + or -, FBO ign meh... J heads a wash may even flow worse if they have has a few valve jobs and the intake valve has sunk. I would guess your hp is about 325, remember the 71 340 real world HP is closer to 310 than the advertised 275hp