Engine Question about block number

[Randy4s]

I am having my 1983 Jeep CJ7 motor rebuilt. The original block is cracked and I am looking for a donor. I found a motor that looks the same, but I am confused about the block number. My original motor says "211C16". I think that means Nov. 1982 AMC 258 i6 / 4.2l 2 barrel. The donor says "805CL13". Mine has the plastic valve cover which goes along with 1982. The other has aluminum valve cover. the manifolds are gone so I can't tell if they were both cast iron. I think this is the heavier version with more counterweight in the crankshaft. What does the L stand for, and what year do you think it is? I read that starting in 1980, the first number coincides with the year (2= 1982", but what did they do before that?

 

[WHATROAD]

The seven figures in your code may suggest that it is from a yj. As I'm sure you know, there is a bunch of info that does not always match up with what you are seeing in front of you. Not every combination of letters and numbers will have an easy answer available. I think the numbers you gave indicate an 88 yj built in may. I don't know what the 13 indicates. Good Luck. As with anything jeep, you're results may very

 

[Randy4s]

Thanks. I think the last two numbers may be the letter I and a three instead of a one and a three.

 

[CDT540]

The build code info can be a bit misleading because they changed the methodology in the late 70s/early 80s that creates a situation where one code can mean two different dates. If you are trying to identify the block the best way is to use the casting number. It is on the driver side toward the front. The attached file will allow you to decode. It also provides the head and crank casting numbers.

 

[CJ]

Good pdf, I'm going to add it to our doc. section.

 

[CDT540]

Here is a couple more that might be helpful