I'm having trouble with my S10. It starts and idles fine but when I try to drive away it coughs real bad and nearly dies. It won't pull its own weight. I've checked all the sensors and checked the timing. I've rebuilt the carb and done a compression check (150 +/-2 or 3 lbs all the way around). I'm at a loss as to how to proceed.
Details on the truck: 1982 S10 standard Cab pick up. 2.8 V6 carburated with 4 speed standard trans. 154,000 miles on the odometer. I have reciepts from the original owner showing he replaced the motor at 152,000 miles but that was TEN years ago. I noticed that the speedo/odometer don't work so the actual miles on the motor is unknown. I have registration reciepts and smog certs (located in So Cal) dated as recent as 2011 so it'* reasonable to believe the truck has been driven regularly since the motor was replaced.
Any guidance or suggestions are greatly appreciated.

fuel pump, filter?

Have you changed the fuel filter lately? If you haven't, change it. If you have, check fuel pressure. Is the check engine light on or flashing?

Yes replaced the pump and inspected the filter. Filter was clean. I don't have a way of reliably checking fuel pressure but with a new pump should I suspect fuel pressure being the issue as it acted the same before the pump replacement? While I had the pump off I hooked up a vacuum pump to the fuel line where it exits the chassis and fuel flowed freely.

I'm wondering if I should suspect a slipped timing chain. The p/o performed his own maintanence on the truck. If he adjusted the dist. to compensate a minor slippage in the chain wouldn't that give me the same symptoms?

Are you losing any coolant? Any white smoke in the exhaust?

No, coolant is fine and the exhaust is fine.

its been my experience timing problems are less pronounced and if its really bogging down it seems like a fuel problem most likely very rich if it clears up at higher rpm. but you said you rebuilt the carb. i dont have a ton of experience with cars with carbs, but i did have a chevy 2.8 in my old jeep and i did a carb rebuild on it. it was too long ago to remember what the adjustments were. i think i would mess with that some more. you look at the plugs and see if they are carbony looking

The plugs were clean.

you watch the timing as you rev it slowly make sure the advance is working properly and not jumping or doing anything else crazy