yep, 205k and still a smile!

 

worked on a lot of 53 blocks none had a crack, we have a 99 with a 53 with 200k on it no problem at all. I just replaced a 53 block with 280K+- with a 5 spd that towed a goose neck almost everyday , it never cracked, he melted a piston and gauled a cylinder from not watching the pyro. most of the problem is, there thin in that area, a good block will be almost a 1/2" thick where as the 53s are close to 1/8"-1/4". if you tap a 55 and a 53 in the area that cracks the 55 will make a thud sound and a 53 will ring.

 

53 block and 221,000 miles with no problem.