ARP 100-1110 1001110 Header Bolts With Hex Style Heads, Chrome Moly Steel With Black Oxide Finish, Set Of 16

I bought these for very tight locations where a 3/8 fit but it was still tight access for the wrench. The bolts seem to be good quality and did provide the additional wrench space I was hoping for.Cons:(1) – Watch out for the length of these. They are longer than the header bolts they replaced which concerned me because I was afraid they would bottom out before tightening. They did tighten up OK for me. If you have thin header flanges they might be too long.(2) – Because the bolts are so long, if you tighten the header up with one bolt, the remaining bolts might not fit past the headers into the holes. Insert all of the bolts you plan to use just a few threads in while the header hangs away from the motor. Then once they are all started you can push the header in until it binds on a bolt, then tighten those bolts. Repeat the process until the header reaches the heads.