Exhaust manifold stud issue

[Gregory891]

Having done this on a number of cars over the years, my suggestions will capture some of what was shared:

1) New studs and nuts (give yourself a chance for success right away)
2) Use a die to clean up the stud threads (both ends) and a tap to do the same on the head and nuts. Don't go cheap on the tap & die you buy.
3) Clean it all liberally (Brake Cleaner or Kerosene)
4) Use stud installation sockets (https://www.ebay.com/itm/4pc-Socket-...RRS:rk:11:pf:0)