What are the best years to avoid the 53 block if there are any?

#53 blocks were used in 98-2002 24V's (and a few 98 12V's but the 12V's dont seem to have the cracking problems)

i think they were most prevelent in the 98.5-00 years IIRC. My 99's 53 may crack tomorrow, but it's made it over 200k so far.

Theres also much info here:

http://www.dieselbombers.com/24-valv...formation.html

And here:

http://www.dieselbombers.com/24-valv...53-blocks.html

i just bought an o1 cummins and found out about the 53 block so i went and checked out mine. it has a 55 will i have any trouble with it or am i in the clear???

You are good to go man....55 is one of the best I believe

alright thanks

I believe the "56" block was the best built, came out of Mexico if I recall?

not quite, the strongest 24 valve blocks have the number 6 real big on the drivers side of the block followed by a lot of smaller numbers, no not the ID numbers found toward the blocks rear, these are right next to the inch tall "6". these blocks were mostly found in generators, cranes and other heavy construction equipment. very rarely are they found in a dodge truck, ive only seen one(and stupid me sold that truck ) a lot of hard core pro pullers look for those block because the wall thickness is atualy .056 thicker then the truck version as to allow for the extra duty these blocks tend to recieve. interally, everything is interchangeable which allows them to build a powerful realible block. Ive only found a couple of these blocks sitting in junkyards or on ebay as most of the applications they were put in are still in use today. the 54, 55 and 56 series were a little thicker in that weak area wher the 53 is prone to crack. Also, just because you have a 53, doesnt mean itll crack. 3 out of 4 of our trucks have 53 blocks, noe have cracked yet and all are over 120k miles on them, mine making 500 dyno proven hp and 219k miles. less then one percent of the 53 blocks made actually cracked. according to TDR, only those blocks with a thickness of .253 or less were prone to cracking, most were .254 or thicker and have never recorded had a crack like the thinner versions. if you want to find out how thick yours is, pull the motor, and drain the block, then remove the freeze plug from the 3 and 4 cylinders and take a diacaliper and measure the external wall thickness and the water jacket thickness, .253 or less, you may eventually have an issue, most crack between 90k and 130k miles if you get .254 or greater, you can sleep a little easier.

Duke a person should be able to do that by just pulling the Turbo an manifold shouldn't he ? Also are you a registred member of TDR ? I've heard they have some good info on there about this subject . Is pulling these plugs the only way to tell ? I may end up doing it to put my mind to rest but I dread it . Lockinstitch has a brace that can be installed but mine is a Auto an right there at the 2nd plug where they crack the most is where the Trans cooler is . Anyway thanks for the info .

what i did was pull the air intake, turbo, exhaust manifold and down pipe off completely, i then disconnected the drive shafts and put a floor jack under the tranny, disconnected the slave cylinder from bellhousing and removed shifters for t-case and tranny from inside cab, drained anti-freeze and oil and take off the oil filter houses and electrical connections, remove intercooler lines,loosened the motor mounts( later on, youll unbolt the passenger side one completely.) after the motor mounts are loose, i jacked up on the right side of the motor only, allowing the motor to rotate slightly towards the drivers side, this allowed me access to the plugs with room to spare. put a block or a jack stand under the right side to help support the motor,. now from here, i took a 3/8 drill bit and drilled a whole into the plug, then took a long punch and pryed it out(warning: expect a little antifreeze to drain out.), used the digital diacaliper and measured it. Once youve got your measurement, replace the old plug with a new one from cummins, tap it in gently and re-install everything in reverse order that you took it off. This is a multi-day project. take you time. I took me about 2 days per truck. now with an auto, youll have to drain fluid, disconnect lines from tranny and the cooler. so it may take more time. I would NOT reccomend this to anyone who is not mechanically sound. By mechanically sound i mean being abel to do way more then just change a belt or do an oil change. Also, having a friend or two to help is adviseable.

Thanks Dukeboy I did not realize the motor would have to be laid over . Well how did you come out on your measurement ? I'm guessing it wasn't any trouble to get the MIC into the right area right below the radius where the block curves out ? Where is the 53 at on your block just curious . Did you just measure the one one between 5&6 only ?

Also You guys can pick up STORM Blocks AG Blocks and Marine Blocks they are the strongest. Storm blocks come with O Rings standard.

I read somewhere how much heavier some of those blocks are does 300lbs sound right ? An I thought if it was that much a person might have to think about different springs up front . Maybe it was the AG block can,t recall .

mine all came out thicker then .254, i measured all of the plugs on that side, i was replacing all of them plugs anyway, why not