89 4.3L Auto trans Timing

A friend of mine has an 89 Blazer with a 4.3L that has 320,000 miles on it and it still runs great. Since I have a 98 S-10 pick-up he asked if There is a trick to setting the distributor timing? I am unsure if there is a set way on an 89 to do this so could someone tell me if there is a certain way to do the timing? I mean is there any wire or anything he needs to unplug then plug back in? Thanks.

yes...anytime u set the timing on a vehicle, u have to unplug the advance to it somehow, in ur case, there is a tan wire with a white tracer under the dash on the passenger side, should be right around the carpet line, u simply unplug it, take a timing light and set the timing, be sure to get it at the manufacturers spec as far as how many degrees BTDC, then tighten down ur distributor and hook up the advance wire

Thanks for the info.