Engine Bolts

[boom3]

OK sorry for the dumb question, I don't have my IO-360 manual handy and am hoping to make a Aircraft Spruce order today.

I would like a longer valve cover bolt to utilize it for my oil cooler brace. They are 1/4 but phillips head and coarser than 1/4-28.

Also looking for a little longer bolt for the back of the oil sump where the exaust hanger brackets attach. By the time you add a couple washers on the inside to clear the casting I'm thinking a little longer bolt would be better. These are hex head 1/4 size but again not 1/4-28.

I can figure out the length I need, I just don't know what they are called in the world of AN bolts.

Thanks!

[caryr]

1/4 - 20 is a standard bolt and thread.

I went to the local fastener place and bought some 1/4 - 20 button head stainless cap screws

they look nice and have a oval head with an allen socket.