Here is what I found having 2 engines, 1 from a 1/2 ton and 1 from a 3/4 ton:
3/4 & 1 ton trucks got a 4-bolt block with the good PM rods, the 1/2 tons got a 2-Bolt block, the connecting rods in the 1/2 ton and 3/4-1 ton engines I had were very different, I suspect the the HD truck rods were from the LS1 but can't confirm because the part-no.'s in the catalog are the same no matter the weight of the truck. I can only tell you what I saw. All blocks were roller camshaft, no roller rockers. The quality of the crankshaft is unknown to me from a production point of view.
There is tons of info about the heads on the interwebs, the older articles tell of all kinds of machining to accept a high lift camshaft, but this issue has been addressed (within reason) with the use of the newer LS "Beehive" valve springs. The Vortec heads also use a different bolt pattern regarding the intake manifold, 8 tiny bolts vs. 12 larger ones. There are 2 casting no.'s both are fine from a street point of view, the 906's had hardened exhaust seats the allegedly flow less at high RPM, the 062's came on 1/2 tons are the "better" of the two.