Engine/Transmission (1998.5 - 2002) 58 Block?

[firefighter_2000]

I have a 99 with over 270k. Unfortunately it has a 53 block. Good news is that it hasn't cracked yet. Was nosing around online and found a fairly good deal on a 58 block here local that I'm considering buying in case the current block cracks. I've never heard the 58 block mentioned. I was under the impression that the biggest and best cast block was the 56 block. Any ideas on the durability and reliability of a 58 block or any other info on it.

Thanks

Craig

 

[Bunyan]

I would have to say it will be fine. Of all the documents I have read the 53 block is the only trouble maker. The Mexican block is the big one. The numbering on the mexican block is, small type, multiple numbers. Like from a type writer. Bunyan

 

[Cowboy]

I was where you were several years ago, a 99 w/ 53 block, ran fine buncha mods, but I started worrying about the "infamous 53" if you have 270k on this motor, IT'S NOT GONNA CRACK unless you hit a building at over 100 mph the 53's only cracked if the wall thickness was under. 250" apparently, yours is over that, or you would have replaced this motor years ago. My humble opinion, based on owning 7 of these great trucks (2 were 53's) drive it till you are tired of it, then look for another one with more options, or different color. just don't buy a gm you will regret it.

 

[HBarlow]

I agree with Bunyan and Cowboy.

I have been reading about cracking 53 blocks as long as I've been a TDR member, the number 53 stands out in my memory. I don't remember any other block casting number as being singled out as significantly better than any other.

Cowboys advice is probably what I would do if I were in your shoes. At 270k miles with modifications your block would have probably failed long ago if it were going to fail. I'd relax and enjoy the ride.

If I was going to change something to protect against future engine failure I would ditch the K&N air filter. Window screens are cheaper and filter equally well. Besides that, a K&N filter does nothing for performance. A K&N filter is a great way to dust and and destroy a good engine.

 

[Vaughn MacKenzie]

56 is the highest cast number I have heard of. As we know the 24-valve 53 blocks crack the most frequently, one story I read was one foundry misread the blueprints and failed to cast in strengthening ribs in the water jacket area where they typically crack. Supposedly more than one foundry cast 53 blocks but it was just one foundry that made the mistake.

I have heard of only one 53 block on a 12-valve cracking.

The blocks cast in Mexico have the highest nickel content and best wear properties and heaviest casting. It seems these were most frequently found in 2wd trucks.

 

[SHobbs]

Information on the different blocks,

53 Block FAQ and Information

 

[Batphreak]

In case a small twist in perspective helps. What you're looking at with buying the other block, "just in case. " You are basically buying an insurance policy, by buying it now you've got the block in case you have a need for it, if you never have a need for it, then you've got a large chunk of iron hanging around. If you can buy it cheap enough that you could re-sell it for at least the same if you change your mind then you really aren't out much money (time value of money that isn't making interest... . blah blah). I'd bet that others are right, if you haven't cracked that thing in 270k you aren't very likely to see it crack. But, if you want to have an insurance policy on it, then at least you have some justificaction in buying it.

$. 02