Fusion 4 + Dub zero

[jz4dayz]

I tried this, and after i took the soles off (used craftsman heatgun at 300 degrees so i wouldnt shrink the booty) the boot is about 3/4 -1" short . After i removed both the dub zero and the Fusion from their OG midsoles, they automatically had this gap. Anyone know what might be happening? It seemed like after the glue stopped holding the booty in there(after removing the midsole),  it automatically lost about an inch of total midsole size. Ill try to post pictures tommorow when im not so delirious.

TY