Great info guys....I'm digesting it all. I appreciate all of it, and is helping me learn.
Now that i think about it and go look....my 86 CJ7 and 89 YJ have both the same cast numbers on the block as the one stated above. My mechanic told me that the C7 has a Jasper rebuilt 258 I-6. If the block castings are that EF 3235444 number then I assume I have 3 different 258's. That is good news....I think.
I am digging this.
And carnuck....earlier in this thread you asked if my D44 was an IFS or straight. i replied straight. i have been googling stuff and learning the difference. So.....I looked at my 44 front and cannot find any numbers on the tubes (long side) on either side. the only number i find on the bolted diffy cap in the low right corner says 44-1F. Does that mean floater? Is that rare? Maybe I'll keep everything the same and make this a classic resto. Daughter can have a different, later model J truck......I will get the hang of this stuff yet.
Thanks guys.