stalls when gassed...

[PKRWUD]

The screws you are talking about are likely the idle mixture screws. To adjust them,
1) Gently turn both mixture screws in until they bottom out.
2) Back them both out 1 1/2 turns.
3) Warm up engine
4) Turn idle speed down as LOW as the engine will maintain.
5) Adjust the screws in two round trips (adjust one side, then the other, then come back to the first side, then go back to the other side) to get the highest RPM.
6) Add an aditional 1/8 turn out for each screw.
7) Reset idle speed to desired level.
8) Shut off engine and check that both screws are the same. If they're not, set both to the average of the two.
9) Restart engine to check idle quality.

As far as having trouble with hard acceleration, this could be several things. What is the timing set at? If he was sitting at a traffic light, and the light changed, and he just floored the gas, what would happen? What about if he was on the freeway and floored it? Lastly, if he were to come to an unexpected panic stop, would the car stall?

Do you have a vacuum gauge? If you can get one, you'll be able to do much better diagnostics and tuning.

As far as the temp goes, is this being confirmed with an aftermarket gauge, or the stock one? What temp did the t-stat open at when your friend checked it?

Take care,
-Chris