I have a 1995 Chevy Silverado with a 350, I changed the sparkplugs and truck ran fine. Put about 300 miles on it and it started to studder on me when I would accerlerate. When in park and you rev it up runs smoother then silk, once you put a load on it, it starts to run crappy. So I re-timed it changed the cap, rotor and wires and still runs like crap. Changed the fuel filter still runs like crap I am at my whits end...please help.