I have a 38' fountain stock 502 staggered. Last year I noticed all the bolts on the forward engine bell housing missing, turned out 4 were broken 2 missing. On disassemble I found bearings bad in bell housing and aft at transom. Input shaft also appears bent. U-joints are good. The drive shaft is solid with no slip joint. Is a solid drive shaft common set up?

Any Ideas what could have caused this? Could it just be wear boat does have 750hrs on it. Should I consider getting slip joint added to drive shaft?