I put a 94 4.3 vortec in a 95 blazer I got it to run ok but it stalls all the time how do I fix

 

You have to determine why it stalls... Under what conditions/circumstances does it stall? Your post is very light on details...

 

it feels like it is surging all the time , when you let off the gas it stalls when I put the distribitor in, I brought # 1 cylinder up on compression and installed the distribitor I think the computer sets the timing I am old school last engine swap was 55 chevy things have sure changed, this thing is fuel injected with a computer ,can"t set timing or idle

 

You should be able to set base timing on a '94. But you have to disconnect the timing connector that is located on the passenger side of the transmission tunnel inside the truck right at the top of the carpet (may need to pull the carpet back to see it). Once that is disconnected, you set the base timing just like any other HEI or points style engine.