WAY too much boost. Whats wrong?

[FastGS-T]

Ok finally got my car running after a head gasket install. Took the car for a ride, boosted wide open full boost pegged out my gauge when my mbc was set at 15psi. so i took the spring and ball out of the mbc to run off the wastegate actuator, and still full boost instead of the 10 pound wastegate spring. Whats causing it? or am i just doing it wrong?

 

[1991GSXAWD]

its possible that your wastegate is stuck/frozen,i would check its movement also run a vaccum line from manifold to wastegate and see what it will boost at, you should see minimum boost

 

[FastGS-T]

Well I just replaced the exhaust housing on the turbo w/ one from ebay. But the wastegate flapper would move freely before I installed the housing. What could cause the actuator not to push it open??? If it is stuck do I just manually move the actuator myself then drive it and see?