I bought a new B&M Holeshot t/c with the balloning plate and noticed it didnt have a flat plate on the back of it. On all the Ford C4 t/c Ive seen they had a thick plate that was the balloning plate. My B&M didnt have this plate, just had some perches welded on to bolt it to the flywheel. Are chevy t/c different?

The anti-ballooning plate is welded on the transmission side.