Hey all, I have owned mostly first gen trucks, with the exception of one 95 12V 4x4 only had it for a few months. I now have the opertunity, to buy a super clean 1996 12 valve with 115,000 miles on it, I have done about 3-4 hours of research on the 53 block, and to be honest I am more confused then ever. My question is what year or even year and month did the 53 block hit the market ??? And where is the actual stamping on the block ???? I will use it to pull my 30 ft car trailer and I like to run them hard once its up to temp, please help I need to either buy this truck or continue the search. ~~~~Canucktrucks

 

53 blocks started production in may of '97. Unless your '96 has an engine from a later truck it wont have a 53 block. Even if it did, the 12 valve 53 block is different from the 24 valve 53 block and does not have the same cracking problems. If you are still concerned the 53 will be stamped in several locations. I generally look at the drivers side of the block just above the oil pan. And if that doesnt work call cummins with the engine serial number and they will tell you everything you need to know.

 

I cant argue with the dates you claim and have no reason to doubt your info on that however I have seen a 12v 53 block that was cracked in Piers shop.
Yes its rare ( rare enough that I would buy one if it was in the right truck) but they are not immune to it. To the OP, I would say if the truck is what your looking for at the right price go with it even if it is a 53 block.

 

Didnt mean to give the impression that the 12 valve 53s are immune to anything, the problem just isnt nearly as bad as the 24 valve blocks. As far as I know they still have thinner walls than the non 53 blocks. I too have heard of several cases of 12 valve 53 blocks cracking. I cant prove it but I would imagine if you look hard enough you can probably find some non 53 blocks that have cracked as well. I have a 12 valve 53 engine in my truck and I have never had a problem with it, and wouldnt have a problem with buying another 12 valve 53 engine. Just my $0.02

 

It is just strictly odds at this point. 53 blocks in 12v's run for a half year, 53's in 24v ran for 3 years or so. Given same production each year (I suspect more trucks were made in the later years, but am just guessing), you have atleast 6 times the number of 24v's than 12v's with 53s. Naturally, you have 6 times the chances of coming up with a cracked 24v.

Moral of the story, both engine can have cracks, neither are enough to deter (me) from a good truck.