My brother needs a column shift lever arm for a 68 Roadrunner. I have a column shift arm for a 70 Belvedere. Are they the same part?

They are slightly different. The 70 shifter levers are bent at a sharper angle and most were satin chrome plated. The 68-69 B-body column shift levers have less of a bend and were shiny chrome plated. You could probably swap them if you absolutely need to have a shifter lever to move the car around, but otherwise I would keep a look out for a 68 or 69 shifter lever.

Thanks