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.