I put new chains and rubber guides in, I used a Napa elimination kit and it had everything in it. The bolts are small, 10mm, I didn't see anything that looked like it was hitting. I am leaning toward a new head because I don't know if it has ever been overheated. The Monty was given to me with a loud clanking sound, thats when I found the timing chain worn the first time and the guide broken. The guide bolt was broken also. I put the balance elimination kit in and had been driving it for about 7k miles. I will get some pics of the pistons tomorrow and see if I can get them posted.