Head Lights Raise Unevenly

However once I put the new 427 engine with a comp cam, no longer will the headlights or wiper doors come up without getting  the RPM's up and then they come up very slowly. The Cam made the vacuum weaker. 

Just wondering is their a vacuum booster that could be installed to make the vacuum work better. 

Usually the problem is in the relay leaking or vacuum hose.