stalls in all forward gears and not reverse

Does it stall out slow or right away? Will it idle in neutral? You say it's a standard transmission and not an automatic. If standard, it should stall out in rev the same as 1st. Other things that can cause stalling is you Idle control valve. Again, if it's a standard, the clutch does not care if your in idle or 1st. Now if you stall when trying to move forward and it stalls that way, you maybe in two gears at one time. I would go to an ATRA shop and have them check it out. Something does not make sense.

go to another shop and have them check it. Roy