so when i bought my 94 blazer in december it had proper oil pressure but i have done 2 oil changes since, first time i put 10w-30 and the pressure dropped a little not alot, then just recentely i changed it agian (agian with 10w-30) but this time I added a restore additive and nowit's about 1/3 of what it should be when i get up around 40mph, I added another 4 cylinder restor to it to try to thicken it a little and added a little more oil.
but I have no blue smoke coming out of exhaust and there is no oil leaks any were.........should i just dump the oil and try 10w-40? or should i chance it and go to 15w-30? I don't want to cause damage cause i don't have enough $ to fix a siezed engine, also no overheating occurs

 

In all of that you never mention "what it should be when i get up around 40mph".

GM defines minimum oil pressure as:

 

hhhmmm.......well when i got it, it was running around just abouve 40 psi for 40 mph which was like 1500 RPM......wow so i gues it was working normally but i have added about 1 1/2 quarts on top of the usual 4 quarts at the oil change..........hhhmmmm i might be a dumb something
so is this accurate for a 94 4.3L v6 vortech?

 

Haha wow...if that's GM's definition.....either my gauge is toast or my engine loves it's oil...

 

Those are minimum oil pressure levels. If you were below those values, damage could occur.

Depending on the filter size, you should use anywhere from 4.5 - 5 qts at an oil change to get in the proper range. 5.5 qts may make it quite full, but probably not over full.

 

ok, it's just when i first get in it and get it around 1500rpm it stays around 40 psi but after driving around for about 5 min the pressure usually drops to around 25 psi for 1500 rpm

 

Sounds perfectly normal.