Slight road block mounting exhaust manifolds, are studs tapered?

[weider1717]

Hey guys, I put all new correct oem hardware on the manifolds new exhaust studs, bought new bolts that screw onto the studs and new springs.

question is are these studs tapered? when I try to screw on the new bolts to the studs they go a little way then stop like they're tapered but the bolts are a old part number so want to be sure they are correct.

the old bolts also do the same do part way then stop so wanted to make sure they are supposed to be like this.

sound familiar to anyone thats been down this road?

thanks!