Good compression and proper IP timing should handle acceleration through about 2000 rpm. You should have at least 5 psi by then and max boost by 2500 rpm.

Remove the turbo air inlet pipe and check for play in the turbo shaft. The impeller blades can cut you so watch what you're doing. Anything more than just perceptible radial play is bad, any axial play is bad.

Remove the ALDA temporarily to see if the IP has more to give as is. It's your choice whether to adjust or shim the ALDA or go without it.

Sixto
87 300D^2