Getting down to the nitty gritty is part of any build and as the crew of The Build get deeper into their project, the more nitty gritty they come across. With the engine block of their 1965 Malibu SS pulled from the frame a few weeks ago, it’s now time for the disassembly to occur. But before that can happen, it’s decoding the block and running a leak down test on each cylinder. Check it out in the video above.

After pulling the engine from the frame, the American Modern crew were able to decode the block to discern that it is a 1969 CE coded Chevy 396ci big block, meaning the engine was either a warranty or a crate engine replacement rather than the vehicle’s original engine. Because the crew wasn’t going for a numbers-matching restoration, this fact doesn’t matter much, just so long as the engine works properly.

To make sure that everything is running smoothly before the tear down, Claims Specialist Rick Drewry runs a leak down test to find any hidden problems related to air leaks in the engine.

With each piston at top dead center, the leak down tester is attached to the spark plug port to measure the rate in which air is leaking from each cylinder. The compression chamber of each head is filled with 80psi of air.

In the end, the cylinder heads showed that air was leaking down into the block at a rate of 25 to 30 percent, revealing wear and possible issues with the rings and cylinders.

This means more work for the American Modern crew but nothing that can’t be assessed and handled once the engine tear down begins.

Be sure to tune back in next Monday for the beginnings of the engine tear down.