U joint bolts

This is a pic of it before I tightened them. Now with thw angle of the strap going over the bigger u joint, when tightened down it only makes it to where I can only SLIGHTLY get a wrench around it and no way a socket since its so close to the strap which causes bolts to get stripped (trust me lol). So I need some u joint bolts that are allen key heads so I can use a socket amd not strip anything. But I need info on the bolts to find another one that will work. Anyone know where to find this?

