Being your running I'm assuming 1/8th mile that 4.88 should be fine. If you were to run 1/4 mile they might be a bit much.

What stall is your convertor?
Do you know the current chamber size of your 906 heads? The Edelbrock should be right around 50lbs lighter for the pair. If their camber is smaller than your 906 than that will gain you a little compression as well.