I bought a used 98.5 and have been looking to see if it's a 53 block but I can't find it anywhere. The only identifying markings I can find is the letter A on the passenger side right about where the 53 is typically found. Is this a decent block? I've heard of the super stout Mexican blocks but I can't find anything about this block with the letter A on it.

 

The 53 can sometimes be found on the passenger side of the block also in the same general area. The mexico blocks have a bunch of little numbers scrambled all over the drivers side of the block. If you don't have a 53 stamped on it anywhere....any other numbers are good blocks.

 

Internatinal made some blocks for the ISB 5.9 as well. Only way to tell is remove the timing cover completely and the IN symbol in stamed on the block. If the block is a 53 block the stamped number will be on the front left side of the engine about 4 inches above the oil pan. There is a little square indentation in the block where the number would be stamped. If there is not stamped number you're ok.

 

That article is actually what spurred my question. I have verified it’s not a 53, but I can’t find a series of small numbers but can only see the letter A. I wasn’t sure if anyone knew what this block was all about.

 

i actually have a "b" marked on the passenger side. and small random ones on drver siide.