Decision Made:
Just wanted to post an update with the decision that I made on what route to take on getting our "daily driver" M1008 back up and running.
We first looked at getting one of the new updated AMG Optimizer or the AMG P400 blocks.... those engines sound like real quality motors... but $7-$8k is a lot of money to put into an engine for a truck that we only have about $9-$10k in total.
So next, as I posted in the opening of this thread, I thought about changing to a different "stock" engine, like a chevy 350 or 383. It would have been nice to have the newer upgraded block and heads, let alone the extra power that would have came with an engine upgrade. But in the end after looking at many different engine and parts options, with all the needed parts and by the time everything was said and done it was still going to be $4-$5k.
(Yes, I could have shaved off some of this by finding a "donor" engine etc)
So... this brings me to my decision: I ended up buying a pair of 6.5L heads from a company called
Odessa Cylinderhead out of Florida. These heads are all new castings but with rebuilt parts
(valves, springs etc). TBH the main reason we ended up taking this route...
well #1 we need to get our truck back up to driving condition as we need it... but
#2 I purchased this Pair of Heads for
$500 for Both Heads including shipping. Plus they send a prepaid shipping label to return the cores, and yes they will accept all cores even if they are cracked etc, so long as they have all the parts there, and they don't charge an upfront core charge. This has been by far the best price I've been able to find anywhere, even for just regular rebuilt heads.
(Link to that ebay ad: https://goo.gl/Px6gbQ )
(Looking at their ads again.... they do have brand new heads with all brand new parts (valves, springs etc) for $100 more... https://goo.gl/hpkJs8 - I have contacted them to see if I can switch to those since the others apparently haven't shipped yet...)
Also I contacted Odessa with a few questions to make sure these were the correct heads for this engine and a few other things, and always got a reply back in less than a day, usually in just a few hours.
I hope that these heads work out great and I don't have any issues down the road. But if I ever do I will update my original SS thread I titled
"CUCV 1986 M1008 - In a Real Pickle - Bad Heads - Need Advice" :
https://goo.gl/Yh5Jmu
Thanks Everyone for All the Help, Information, and Advice