info on throttle linkage

So I was messing with putting on a new filter on the car today. and just wanted to check this since one of my buddies had the same problem on his car. I had my girlfriend push the throttle down to the floor normal without mashing it in while I looked down the carb. And low and behold it only barely opens the secondaries. But if she pushes the pedal to the floor and then mashes it in hard it does open them a bit further, still not all the way though.. I thought maybe I could loosen the clamp and pull the cable back a bit but as soon as you do it bumps the primarys open so that isn't going to work I don't think. There doesn't seem to be any slack at all in the cable, It just doesnt have enough travel to open the carb all the way. So I am wondering what I am needing to fix this. A shorter cable, A different bracket of some sort, or what else??? any help, info, opinion? Thanks.

It is a 71 scamp. stock throttle cable and pedal.
408 stroker with eddlebrock air gap intake.
aed carb.
some sort of jeggs brand throttle & return spring bracket.