So picked up the engine for my truck today. Im not really sure what I ended up with. I cant find a 53 anywhere so I hope that is a good sign. The block in my truck has a big 53 on the drivers side lower front of the block. This block has a series of numbers. The tag says it was built 3/3/98 and is rated at 235hp. My tag says 215hp. This engine must have had a manual behind it? My plan is to swap most of the parts from my engine to this engine so I hope I dont have any problems.

--- Update to the previous post...

Oops. I put this in the wrong section. This is meant for the 24valve section. Sorry.

This block appears to be the standard output version of the 1998 24 valve... offered with manual transmission. Supposedly down rated for automatics.

Moved for ya... As for the block its a 53 block... They are known to crack but... http://www.stamey.info/Truck/Cummins53BlockFAQ.htm As for worrying about it I wouldn't worry too hard on it being CajFlynn here has 53 Block as well that crossed over 1.1 million miles and still going!

I believe the OLD BLOCK is a 53. The new block is in the right time period to be a 53 but if it is a 53, it will be so marked. The blocks were not used in any sort of an order & there was more than one block supplier. My 01 has a 55. "Locate the large wiring harness mounted to the block. The cast number for the Cummins 5.9 engine block will be located just below the wiring harness and above the spot where the oil pan meets the block. Engine blocks cast by Tupy feature a two-digit number embossed on the block surface. Blocks cast by Teksid include a longer series of numbers in a smaller size. "Move to the passenger side of the vehicle and look directly below the oil filter mounting assembly. Another instance of the cast number can be found on the block, ahead of the front turbo drain port. Read more: How to Locate the Cast Number on a Cummins 5.9 Engine Block | eHow.com http://www.ehow.com/how_7370476_locate-cummins-5_9-engine-block.html#ixzz1cVq1ma5x

The marking for the 53 block had two place's it was possibly marked,driver hidden by wire loop or below oil cooler. Document and save pictures,I just recieved notification of a settled class action that will pay up to $500 dollars. If your truck was originally installed with a 53 block you should get a postcard.

I just picked the truck up. Havent put it in my name yet. No postcard for me. From what I have read the block I just got is a mexican block. So I should be good to go. Looks to be in decent shape for having 200k on it( on the outside anyway ). Going to pull the head and oil pan to take a closer look.