no, lock washers. i decided just to start cranking one down since the other thread seemed to say the m10 x 1.5 was correct and 1 by 1 they all managed to make it all the way down the stud so that was correct. my manifolds came in a turbo kit and were coated and seems i should've made sure the threads were cleaned up vs just looking at them and thinking they were good to go.
this problem is solved, now i have much larger ones! lol whole other story i'll save for the build thread when the time comes.