MTFCA Forum

I had my engine rebuilt and after machineing my head bolts are a 16 th to long . Im going to 2 1/2 " bolts. Do they need to be grade 5 or 8

Found my answer in the search part of the forum

Just grind 1/16 inch off the end of the standard bolts. As often suggested on this forum, check the the bolt lenght by setting the head on the block without a head gasket and the bolt head must contact the cylinder head rather than bottoming out. Install each bolt in the location that the the check was made. Bolt hole depth varies from hole to hole. Failure to do this could result I. Bottoming out the bolt and cause a lot of trouble.

Art Mirtes

When grinding the end off a bolt, it can damage the threads on the end of the bolt so you will not be able to get it started into the hole, so, before grinding the bolt down, screw on a nut. After grinding off what you need to, bevel around the end of the bolt then remove the nut, which will open up the threads on the end that were flattened and damaged by the grinder.

Another issue that will give you a false depth gage reading is the base of the head bolt hole collects hard packed carbon. I use a small bore brush cut the end off chuck it up in my drill, flood the hole with brake clean and clean the hole. You will be amazed how much crude you will get out.

just sayin'

frontyboy

Not sure what you found doing the other research...

The FORD OEM bolts were actually grade 2/3. You can't buy that grade anymore so 5 works.

The FORD design only has 2/3 of the threads needed to conform to Torque tables of today, (but everyone seems to ignore that.)

The design torque is closer to 35# -38# seating (but everyone seems to ignore that too.).

Using an Aluminum head changes everything.

DO take a dental pick and clean all the way down each tap as every thread actually counts...work with a 7/16-14 Bottom tap if you can as your 'chisel' . (At the time of the T design they were not yet aware...once there has been run in and out a few times you can't really rely on the top lead thread anymore in the stretch scenarios. Thread failure is actually a pancake failure where each thread lets go from top to bottom.)

I know, nobody asked its been a while since a reminder discussion...sorry.

Anyone who replaces a head or head gasket should have one of these in their toolbox -