broke in the new engine- but need help

The tubes! And the firewall at the back, and the steering box on the side, there just aint no way to get in there. Twelve point? I'm gonna try it. I have regular hex bolts on it now. That must be the reason. Do you have extra long ones for the outermost holes on each end? Cause I had water sizzling out the front one and I pulled the bolt and rtv'd it and it seems to have stopped but I wonder if it needs a longer bolt since it used to have studs in there. Now it doesn't, they were this way when I bought em. Should I have put studs in?