Yesterday, I spent some time in chasing out the threads in my engine block and went on to cleaning up the head bolt threads. I have a 55 235 and feel pretty confident that they should all be grade 8. While handling one of the shorter bolts, I noticed it was grade 5. So, I went back over all the rest and found that I could not identify most Can some one help. What I found follows:

All of the long bolts were marked similarly - the heads were marked with 2 concentric circles. I suspect that these are original, and there fore grade 8.

5 short had 2 concentric circles and the letter F.

1 short had just the concentric circles

2 short are grade 5 (Biz bag!)

1 short was grade 8 with the letter F

1 short I guess was grade 7 - 5 radial lines, but they were not spaced equally around the bolt.

V
Bob


BobS46