Another EZ Read reference. This is the Head Bolt Torque Sequence (Pattern) for the BBC, Mark IV Big Blocks, Rat Motors or what ever you might lovingly call the motor. I am an old timer and had a 1969 SS 396 that subsequently got a 427. I am a fan of this motor, they make good power with only a little work and not much sounds as good a high compression uncorked BBC at the drags. I have a ZL1 powered Cobra as no reason to put a lump of Ford Iron into one of those cars. Check that out here – Herb Adams VSE Cobra.

Note : this does not include the extra bolt holes for some aluminum blocks that is in the intake port. These are installed from inside the valley chamber, and typically are a short stud.

Big Block Chevy Head Bolt Torque Specifications

Long Head Bolts 75 – 80 Ft/Lbs
Short Head Bolts 65 – 68 Ft/Lbs

I would also add make sure you torque the bolts in steps. Do a first round hand tight, second round at
50% torque (OK, let’s just say 35 Ft/Lbs) then final round at specs.

For Head Studs or aftermarket bolts CHECK YOUR INSTRUCTIONS, BBC studs are available in a ton of different styles depending on heads and stud diameter (7/16″ and 1/2″).

For what ever you use make sure the threads in the block are clean. It doesn’t hurt to run a tap on every bolt hole (unless for some reason you have a thread insert in them) to ensure proper torque. For some blocks you will have the bolt holes drilled through to the water jacket. Use a good sealer on the threads (ARP, Permatex) something specific for bolts. If you have blind bolt hole use the recommend ARP lubricants on bolts or studs.