Model 12 CAT motor grader engine book....

You really need to post the serial number to get the right info. I,m kind of thinking you have the D318 engine in the one you have and if it is then the D6 8U & 9U tractors use the D318 and a couple other tractors like the 20A 977 loader or even the D318 industrial engines.

The only seriel # we have is 9K9327, the block # is 7B6096

A 9K came out in 1938 so if it has a 6 cyl. engine it would be a D4600 engine but to be sure that the engine hasn,t been changed some time look on the left side of the cyl. block just below the head at the rear above the starting pinion and see if there is a SN plate there or if missing it,s normally stamped in the casting so you may have to scrape or brush the paint or rust off to see it.Also as CC said the intake and exhaust manifolds are both on the right side on the D4600 where the D318 has the ex. manifold on the right side and the intake is on the left or the injection housing side.

Here's a link to Willie's website with head torque patterns and specs for both the D4600 (exhaust and intake on right side of engine/left side of grader) and the D318 (intake on left side of engine/right side of grader and exhaust on other side)

My book for the D318 says tighten main cap nuts to 120 ft-lb and turn additonal amount to get cotter pins in. (someone has penciled in 150 which I would suppose is what you torque them to if you don't use the cotter pins)

rod bearing caps-book says 58 ft-lb same thing-advance to next hole and install cotters.

The only number I have is the unit serial #9K9327 and the block #7B6096