Finally got the unisteer system and started the install. Can't get their bolts into my threaded inserts. Not sure if it's the provided bolts or if I need to run a clean up tap in them. This was an inline six car, so it's got a few decades of crud up in the holes. Anyone know what the bolt size and thread pitch is so I can get the correct tap? Don't want to bugger up the inserts. Thanks.