Ok I been told that the reason my truck acts like it does is because it could be off timing..now my question is how hard is it to check the timing...and what is the correct way to adjust the timing?? thanks

 

Is it HEI distributor or regular vacuum advance? No mods I guess? HEI you have to unplug the 4 prong plug next to the distributor. Regular distributor plug the vacuum and adjust to spec. I think it is 6 degrees before TDC but it's been awhile. I'm sure someone will correct me if I am in error....

 

I believe it is HEI

 

I'll have to get a manual for the 350 TBI as I now have that in my '90 Blazer but I believe that pvollman is correct. There should be a 4 pin EST (electronic spark timing) connector at the distributor. Disconnect that, then set the timing. There will be a sticker on the rad support if you're lucky that tells you what the timing should be set to.