6.2's are awesome. Been around for a long time. Will be around for a long time to come.
It's my opinion that a 6.2 block is stronger (GM for GM, stock for stock) than a 6.5. The difference is in the bore, and in that, the block isn't 'hogged out' as much around the main web areas. More meat in between the cylinders too.
Heads are slightly different, be can be used with all 6.5 peripherals no problem. 6.2 heads have bigger valves and have the potential of flowing lots of air with some work. Pre cups will interchange.
I wouldn't get too excited about the squirters, not a 'priority'..
6.2's came in GM trucks at a time where the wheezer gassers were barely in the teens on MPG. The 6.2 is a MISER in stock form- effectively doubling the MPG of a gasser. As with anything, you start hotrodding it (boost&fuel) and leaning on it, the fuel mileage suffers.
I am doing an '81 6.2 long block swap into the '93 6.5 one ton right now, as a matter fact.