Packard Forum Index » Post-War (1946-54)

Hello everyone,

After putting the head back on my 359 one of the headstuds gave it up and began te come loose... did not make it to 60-62 ft... so i need to repair the threads in the block. Now my question is what is the size of the bolt/treads for what i could find it is 7/16 and 20 someting? The 20 stands for the threadwind? Course or fine? And is 7/16 20 correct ? There are a lot of helicoil sets with diffrent sizes.
Thanks👌🏻

They are 7/16-20 but unfortunately Packard used rolled threads and the replacement studs were made that way. I am not sure if studs are being made for the 359, though as they are longer than the other models, or at least that protrude farther.

Good Morning...When I needed a new stud for my 49-288...I found a good used one at Packard Seattle Commpany...David Moe...425-293-7709. You could also check Max Merritt 800-472-2573...or Packards Southwest 619-726-4605...or Tuscon Packard 520-730-2246. One of these folks will have the stud you need...unless the studs have pulled lose in the block...which is doubtful, I think. Ernie in Arizona