Hello, New to this forum and have a question. A 1987 Chevy S10 pick up (166K miles) was given to me a few weeks ago and I've been cleaning it up and such. It was sitting ilde in a garage for 12 months so it needed a bit of TLC before it would even start. The owner couldnt' tell me the last time the oil was changed but the crank case was full - and it was still liquid. I drained it out, removed the fram filter and put in 4 qts of Q-State 10W30 and a Purolator filter. It fired right up and suprisingly no black smoke or funny noises. I have been using it on the weekends and have not noticed any smoke or piston slaping or odd noises. What would be a good choice of oil for an engine this age? It's not an everyday driver but it still has some life left in it. My fear is that with sitting for so long, [censored] and sludge have built up in it. The oil has stayed clean with 1400 miles driven. One more thing. What is the fill capacity with a filter change on this engine? I've seen 4qts and 3qts? Any suggestions, advise w/b appreciated. Thanks!