Smoking during hard acceleration

Hi I have a 92 Mitsu galant 2.0 sohc with 220,000+ miles. I got the car from a guy that overheated it and warped the head and blew out the head gasket. He put it all together and he didn't tighten the cam gear bolt. I got it running and it ran great. Everything worked. Then it started running crappy. Come to find out it was the ecu. Replaced it and it runs great again. I changed the oil and went on a road trip. About two hours down the road I exited the highway and the oil light started flashing. I stopped at a gas station and checked the oil and it wasn't on the dipstick. I put 4 quarts of oil in and it stopped ticking. During the trip I kept checking the oil and adding it as needed. I figured it was the valve stem seals from sitting so long. I just changed them and it still smokes under acceleration. Gets great gas mileage but still uses oil. I have no external oil leaks. Do you have any clues to what it could be? It doesn't smoke any other time, even at start up. Only when you rev it up. Thanks, Mike.