Swapping gears in Tiagra 30

[gstours]

Hello out there Shimano people;   I was wondering if the gears in the Tiagra 50 will fit the 30??  As I would like a little slower gear ratio,  I,d sure like to know??
    Do they seem similar?  somebody should know!!!!!!! I have ever seen the insides of a 50 yet.  I realize the cost may be high, but is it do-- able??? Id appreciate some info.    thanks     gst.

[alantani]

http://www.cals2speed.com/whatsnew.html

[Tightlines667]

The 30A and 30WLRSA are interchangeable

The 50A, 50WLRSA, and 80WA are interchangeable

Otherwise, I believe you have to order the gear set from Cal