Year to year /6 compatibility

Hi there,

I've been a browser/occasional poster for a while now. I actually have an '84 D100 with a /6 and was directed here a few years back when I had a lot of questions about the slant 6 that's in my truck; so far this has been an incredible resource for me. It's a 4 speed A833 truck, and ideally I'd love to keep the slant. About 9 months after I got it, the truck started smoking quite a bit. After a valve adjustment/new seals and no decrease in smoke I decided to run a compression test (probably should have done this first) to find only 25psi on cylinder #5. I tried many different cheap "fixes" (longer freeway trips, marvel mystery in the cylinder, etc) to no avail.

I was planning on possibly just putting in a new set of rings on cylinder #5 but decided to try to do this right and actually do a proper rebuild. The only problem I have is finding a place to work/ability to have the engine out of the truck for more than a few weeks (it is currently still drive-able, although I avoid longer trips). I'm looking to put together a slant from another vehicle and then just swap it in a weekend or two. Since I'm going through the trouble, ideally I'd like to go with a "best" or "better" year(s) of the motor. Any suggestions for years to look for or avoid? Compatibility into my truck would be a little bit of a concern too, although from what I've read, most, if not all of these motors should bolt right in and up to the transmission as well. The motor/truck would just be kept mostly stock with the exception of the electronic ignition and Holley 1920 that I have on it now.

Thanks in advance for any help you guys can provide.

-Brandon