ok, so i'm looking at buying another truck, and i found myself a 98.5 2500 qc, and i know to look for the infamous 53 block, but my question is this, from what most of my research has shown me, the blocks only seem to crack while towing. Is this 100% true, or have they been known to crack under modification? and how heavily modified? any answers are greatly appreciated

 

https://www.dieselbombers.com/24-val...-53-block.html check out this thread and see if it will answer your questions

 

53 blocks get a bad rap IMO but yes they are prone to cracking and it's cause by heat cycling not from modifying the truck. If the truck has any sort of higher milage on it once again IMO the problem should had reared it's ugly head by now... My dad and I have both owned 53 blocks with no issues and my dads truck is still goin strong pullin cattle all day every day with 357k on the truck.

 

my buggest worry is, this truck will be getting a set of twins, with alot of other work done, i'm taking a shot in the dark, adn say maybe in the 600, when i'm done, adn i would definitly hate to do all that work to have it crack on me

 

Sounds like u answered your own question.

 

so very true, but what i have been reading is several trucks in the 500 range that never had a problem, i think i shall just hold out for another one, thank you everyone for your answer, much appreciated

 

I know a guy that has a 53 in one of his heavily modded pulling trucks. The block itself i believe has over 400k on it, and even with running about 700hp he has not had that block crack. I think it all depends on how lucly you get, and what day of the week the block was manufactured on

My block has NO numbers on it at all... Its a mystery. Im told that the blocks without numbers were built in the mexico plant, and are supposed to be bulletproof due to more iron and less crappy metals...? Thats just what i've heard.

Good luck man!