7 1/4 rear strength

To give you and some members an idea on this subject my 1970 318 2 barrel equipped with an automatic trans Barracuda came with a 7 1/4 sure grip.... at 140.000 miles my spider gear retainer broke after I beat the chit out of it for 3 years.
I think a standard trans is harder on them.. plus these cars was lite and was not meant to carry 4 people. If these 7 1/4's was rebuilt correctly new bearings (inner and outer and pinion) a stock 318 210 hp and not abused will indead hold up.. I will be going 8 1/4 when and if mine goes away.