This weekend I started working on these two 806s that I bought a few years back that are a mess half tore apart just a big heap of parts! So anyhow I have twork rebuildable 361 engines and one parts with a hole in the block! Now I was thinking about getting new head bolts when I put them back together! Now the question is one engine has square bolts and a thicker shank about a inch down from the head then smaller the rest of the way to the threads one engine has a 8 point head and the same shank deal as the first now the third has grade 8 bolts with no difference in the shank! Now which bolts are correct? Can I use the grade 8 bolts?