just did one of these myself on my truck. if all was done corectly by mechanic probably somrthing simple as a bad spark plug wire, or repositioning of the wires after the job left one to chafe. how old are the wires? could have benn put in wrong firing order also? was this a competent shop, or a shadetree mechanic who did the job, there are other possibilties of problems, some simple to not so, but a competent shop doing the job the right way would decrease the chances of the probability of such problems. two things i can tell you, from my experience doing these, use delco gasket only, been revised with sealer in problem areas, and make sure head was milled, pressure tested, and there were no signs of porosity. all these being done, probably something simple. jon-
jonnoboy@aol.com removed mechanic, gone parts specialist ase certified