Intake gaskets
this is the reason the magnum small block has the intake bolts verticle, it makes it easier to pull the intake into place. your problem is not uncommon. you don't notice it as bad with a stock cast iron manifold & stock int bolts, as the stock int bolts are sort of self starting. what i try to do if useing supplied end seals is to use a long tapered punch in the bolt hole as a pry bar to align the bolt holes. if it were me i would use a good grade of silicone on the end seals & be done with it. hope this helps