/6 cost
if you dont have a rod knock or blowing black smoke out of the exhaust, then i would find a good mechanic to diagnose your problem. you can research most garages online to find customer complaints. i picked up a running slant 6 off craigslist for 175. from an 85 van. i just have it as a spare for right now or for a possible performance buildup project.you should search for spare parts if you have a place to store them as they are getting harder to find. who knows you might just need a valve cover gasket and some carb tuning.