Where is that dreaded "53" on the block?

[Cumminalong]

Here's where you want to look to see if you have the dreaded 53 block.

[Kilch123]

Yep - also in the same place on the other side...

But, just because that  tattoo  is on there doesn't necessarily mean it's gonna crack...

A lot of what I have read points to the fact that people that have experienced failures had the following in common:

• Colder climates
• Not using the block heater
• Not allowing the engine to warm before placing under heavy load (trailering or hard driving)

Apparently, if you allow the engine block to warm gradually, the block will typically not crack.  However, if you romp on it while the block and coolant are still cold, you can cause the central part of the block to expand (the area around the cylinders) before the outer shell of the block (water jacket) which causes warping and stress in the thin parts of the block

Then it may form a crack near the rear 3 freeze plugs on the passenger side of the block just above the oil pan, which will leak coolant