If its a 73 its valuable, 74 is aswell. But its a completely different animal than a 79-85. Im not a big fan of atc 70s. I know the recoils are different. 73-74 is thin and 79-85 are thick, 73-81 are 3 speed, 82-84 is 4 down and 85 is 4 up.
1983 ATC 185s 200 jug bored .20 9.5:1 Naumura piston. Fast as ass when its not stretching the drive chain or stripping hubs.
1986 ATC 250ES. *Total garbage trying to sell it*
1983 YTM 200E. Runs good, forks are super bent but aside from that its mint.
1984 YTM 200L. Barn find, everything is mint except the bottom end is bad... *waiting on a new engine*