I just want to confirm which ones I need before I order. I'm going to be putting my shortblock back together and want to use the right threadchasers. I believe I need the course ones and not the fine. Can anyone confirm?

Thanks,
Merim

 

Coarse or fine refers to the pitch of the threads. You need the thread chasers that match the thread of the bolt holes. You probably won't find many fine threads in an engine block. That would be like 1/4x28 as opposed to 1/4x20. hth

 

Use a tap.