Considering their battle powers at the start of Z, I'd assume Yamcha remained the same, likely due to his relationship with Bulma and his baseball career (it was Toriyama's idea and should be taking into account even when purely discussing the manga) would've taken priority; whilst Kuririn became decently stronger. Tenshinhan is hard to judge when he was already far above the other humans and far below Goku/Piccolo before, though I'd assume he got similar gains as Kuririn due to his focus on training.
Roshi may have gotten stronger when taking Super into account, though I'd say there's nothing to suggest it rather than the numbers being a bit too close and Roshi's off-hand surprise at Kuririn being far above him.
Yajirobe wouldn't have gotten any stronger. Chaozu probably did, though likely by just a minimal amount considering how close the BoZ numbers are together and he usually tends to peak far earlier than his peers.