Edelbrock tuning issues

if it's the performer then it's not very big at all. they spec it out as 420/420 and 204 @ 50

unless it's a performer plus... then it's an entirely different beast and likely too big for what he's trying to do.
The cam was allredy installed when i bought the car. But i really do not think its a preformer plus.

Could it be too lean on the mixture?