Thread: Head studs

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SBC head studs are three different lengths. As shown in the pictures below, there are 16 short ones (eight per side), used in the lower holes, 4 medium lengths (2 per side), as annotated, and 14 long (seven per side) bolts that are across the top of the head. This is a Dart block - but all SBC will look similar.

The kit shown is from ARP (Part # 134-4001, I think). Placement is critical as is making sure the holes and threads in the block are absolutely spotless. I typically ask the machinist to chamfer the holes – not all will agree with this but I have not had a problem with a slight touch here and it eliminates any “snag” points – especially if block has been decked.

I run chase/cleaning tap with cutting oil down the hole when the block comes back from the machine shop and then a small bottle brush (get them at a Dollar Store – they’re like four for a buck) with hot soapy water down each one (I like Dawn – but get your own bottle for this to keep peace in the family – trust me here) followed by compressed air and then a solvent on a different brush. I use acetone (wear gloves as its killer on the hands) again followed by compressed air. Be sure to wear goggles too as it can be really bad in the eyes! Last step is a clean fine thread, absorbent cotton rag, like a white T-shirt, dipped in oil. I wrap a small piece on a straight screw driver and gently “thread” the rag down and back. If any dirt or crud comes back – repeat the above until it’s really clean. This adds about an hour to the assembly process and I believe it to be time well spent as it allows me to carefully inspect as I go.

Now you’re ready for the head studs. Do not put any additional oil/lube on the studs. If you’ve done the above correctly, the studs thread nicely and torque perfectly. I have seen people pour or squirt oil in the holes to a point where the studs will not tighten correctly - remember, fluids do not compress. And for heaven’s sake, don’t use WD-40.

Have Fun,
Glenn