So much about 58RA strung.Some guys here asked the range of SW and actual flex. Here are the specs of the frames I own(owned) unstrung/strung:
TC97 18x20 RA66/63 SW301/330
TC97 18x20 RA64/62 SW301/331
TC97 18x20 RA66/62 SW299/333
TC97 16x19 RA66/62 SW296/326
TC95 RA63 16x19 RA65/62 SW301/328
TC95 RA63 16x19 RA63/61 SW301/331
TC95 RA63 18x20 RA64/62 sw305/335
TC95 RA70 16x19 RA68/66 SW292/320
TC90 RA70/66 SW290/320
The strung SW and RA is measured with overgrip and dampener. Some frames have leather grip, some PU.
Hope it helps.