2003. 2wheel dr 150 p.u. I. Put smaller tire on because back problems getting in .now at 60 mph dash odometer reads 69 mph . Is there something I can do . So odometer would be correct.

There are different speedo gears in the transmission available that will allow for some ratio changes in the diff so check with a dealer spares to see if any are available for your vehicle
when you say smaller tire , is it a smaller diameter rim that was fitted
if that is the case by fitting a larger tire case may get back closer to the correct reading
by that I mean for example a 195 25 r14 case can be replaced by a 195 95 r14 case as the difference is in the 25 to 95 measurement
the 25 measurement makes for the rim almost touching the ground where the 95 dimension stands the rim well up off the road and because of that the distance covered in 1 revolution is far different to the distance covered in 1 revolution by the 25 size tire
that solution may put the car back too high for your back problem so if the gears replacement is not possible , then a last solution may be to find an instrument repair shop and have the gauge re- calibrated to the correct reading according to the speedo gears in the transmission
if it is auto with a VSS unit that signals the speedo there may be changes in that area that are possible

Have odometer calibration