Blind mag centerfeed question

I'm putting a staggered feed stock on my centerfeed gun. Long action gun that's hinged now but converting to a blind mag, my question is are the retaining tabs for the long action vs short action magaznes different. My model 12fv L tab is to short to reach the rear action screw on the new stock. I had ordered a new one directly from savage and asked for a long action tab but go a exact copy of my model 12 tab. Anyone have a long action and a short action blind magazine gun help me out here? Thanks.