I used 3 of these bolts to replace the 3 head bolts when I modified my 8BA oil canister to fit the headbolt locations on the aluminum heads. Will probably work for you also. Now I don't have to remove the headbolts in order to remove the canister.
I also made a spacer to raise the canister 1/4 in. above the bolt head, if needed. I didn't use it and it's for sale if you need it. It fits on top of the" New" headbolts and gets hidden under the canister mounting flange. Thanks, JIM
You may want to try Tractor Supply. I think they have a section that has bolts and nuts also bushing and many other hard to find items. JMO