Chevrolet Repair: Smoke coming from tailpipe, z 71, couple bottles

Question
I have a 1994 Z-71 4x4 and it has 153k miles on it so far.  Runs great and doesn't appear to be anything wrong with the truck so far.  The only problem is...  As of about 1 month ago, I noticed smoke coming from the tailpipe.  Usually I don't even see it unless I am at a stop light or stop sign.  It happens when I go from a dead stop.  It smokes very heavily for about two seconds and then stops.  I thought it was bad gas, so I put hi-grade petro in there.  I also thought it may be that I needed to get my oil changed.  Not sure what to do currently.  Any advice you would give me on what it might be?  Thanks and have a good one!

Answer
Hi Joey,
The color of the smoke could help narrow down where it is coming from, but if it is oil, it should show up on the oil level.
I would guess dirty injectors, and would use a couple bottles of injector cleaner through the tank first.
Valve guide seals are always a possibility, as well as PCV valve.
Van