[Gearhead999]

Glad to hear you purchased quality parts.
The shoe assembly should be centered.
Did you check the new wheel cylinders to the old ones. Are they the same size, length??

When you say the shoes at the top spring back. Are you talking about the top of the shoe where the half circle fits against the top center post, above the wheel cylinder??
If you are, both the front [primary] and the rear[secondary] shoes should be snug against the post. If one or both of them aren't, there is your problem.
If the secondary shoe, rear, is away from the post it is usually caused by the parking brake being partial on or too tight.

Later.....