I have a 1980 20R Engine and a 5 speed L52 trans. I'm not sure on the mileage. The engine has a Weber downdraft electric choke carburetor, and a Pacesetter header on it. It has good compression, and runs great. The shifter on the transmission is a little sloppy, but otherwise runs through gears just fine. I'm just selling because I'm swapping in a 5VZFE. I'm asking $300 for the complete motor with all accessories, hoses, belts, etc. and $75 for the transmission. Or $350 for both. I'm located west of Ft. Collins, but can deliver within reason.