I don't think you can use the 496 (gen VII) 8.1 specs. That engine has 2 extra head bolts (to help fix the common blown head gasket areas) and the bolts are a 10mm x 1.5 pitch metric bolt in 3 different lengths (103mm, 86mm, 52mm). They actually have a different torque degree/angle for the shortest bolts too. Interesting stuff.

I don't think the previous generations of BBC were metric if memory serves?

Though I don't know much of anything about the 496, I pretty much assumed it was significantly different.

Prior big block Chevy's were not metric.

I guess someone would really have to go through a significant engineering exercise to figure it our for the the previous generations.

I looked and I couldn't find anything on older BBC using torque angle for the heads. With as popular as the BBC is you'd think someone has figured this out by now. Torque angle can be applied to the "one time use" torque to yield (stretch bolts) that the 496 uses, and standard old school bolts too according to what I've read.

Just for kicks, someone should torque all of the bolts down on one head to 50# and then measure the average angle that it takes to get them to click at 80#. I suspect this would be a very good way to torque the head, 50# + xxx deg. With this method, it wouldn't matter if the washer turned or not. I don't happen to have one here in the shop or I would give it a whirl.

For the record, i have torqued every BBC head that I have ever installed at 30#, 60# and final to 80# and have never had an issue with bolts or studs.

That's a good idea Snapmorgan. I think I would use the 496 as a starting point meaning torque all to 22lbs and then go from there.

After doing several heads, you could come up with a good average degrees for each bolt length.

https://www.fixya.com/uploads/images/7b0c7d2.png

The only time I've ever seen a washer spin, after the bolt or stud being torqued, is when the bolt or stud is to long and has bottomed out in the thread before reaching the head.

Automotive Racing Products Tel: (805) 339-2200 1863 Eastman Avenue Fax: (805) 650-0742 Ventura, Ca 93003 www.arp-bolts.com INSTALLATION METHOD FOR HEAD STUD KITS 200,000 PSI 7/16 inch Diameter 1. To ensure proper thread engagement and accurate torque readings, clean ALL threads in the block. Chase if necessary with ARP Thread Chaser. 2. Clean and inspect all hardware prior to installation. Look for obvious defects or shipping damages, plus proper fit, length and dimension. 3. If the cylinder head studs protrude into a water jacket, lubricate the block threads of the studs with ARP THREAD SEALER. 4. Screw studs into the block “HAND TIGHT ONLY”. NOTE: LOCTITE MAY BE USED IF A PERMANENT MOUNTING OF THE STUDS IS PREFERRED. THE FASTENERS, HOWEVER, MUST BE TORQUED PRIOR TO THE LOCTITE SETTING UP. 5. Install the cylinder head(s) and check for binding or misalignment. 6. Lubricate the stud threads, nuts and washers with ARP ULTRA-TORQUE FASTENER ASSEMBLY LUBRICANT. Then install the washers and the nuts onto the studs and tighten them hand tight. ARP recommends using the ARP ULTRA-TORQUE FASTENER ASSEMBLY LUBRICANT that is provided with each kit as opposed to motor oil. This is due to higher friction on the studs as well as inconsistencies in the clamping force of the fasteners when motor oil or other low quality lubricants are used.