Smoke at 5500 wide open

Im looking into buying a motor swap from a friend of a friend. Its a d16y8 outta a 96 sol SI. Motor has 120 on it, the 99 ex trans and clutch have 25k on it, and axels and ecu for $400. He has no need for it, and the friend so go cheap to him. BUT anyway, we got to talking he sayed it smoked greyish smoke he could barly see out he rear view mirror, he was racing someone i guess and was at 5500 and wide open when he saw the smoke. My concern is it is a work headgasket, but he also says there he oil is dark brown, nothing outta the usualy i guess and it doesnt burn oil. so i, sorta puzzled, maybe you guys can ease my concerns.

if it is blowing smoke that is, i guess, dark at high RPMs then the car running rich at full throttle. Most cars do that at full throttle when they are in their older years. U can try replace intake filter or O2 sensor i believe and it might help.